Aquatic Plant Forum banner
Not open for further replies.
1 - 5 of 5 Posts

· Registered
270 Posts
Discussion Starter · #1 · (Edited)


By Christian Rubilar

There is a very close relationship between fertilizing, uptaking and algae. The purpose of this work is to explain how does this relationship works. Even this is a complex subject with a lot of new ideas, I will try to be as clear as possible.

The ideas I will explain had been discovered during my work as aquarium gardener and had been confirmed with positive feedback during the last 5 years at the most important Spanish speaching forum, so this is not speculation. The MCI had over 100.000 reads since it was published and algae is not an issue any more for us.

I believe that one of the mayor issues about algae is confusion. If we read about them in books, we can find that very important authors assert that some of them blooms because of excess of No3 or Po4. When I read this I understand that this person has no idea why algae blooms.

The most popular fertilizing methods don't take enough attention to algae. Some of them focus attention in Co2, other asserts that to reach the balance will solve the problem. It just doesn't happened!

On the other hand, the EI asserts that algae blooms because of lack of Co2, Light or fertilizing. The idea is well oriented, but incomplete.

Proper Co2 and light are too basic, so I prefer work with them as prerequisites.

About the lack of nutrients, the EI asserts that algae blooms because of lack of a nutrient and propose to add this macro/micro to solve the issue. I disagree with this approach. In the following pages I will explain why.

A. Background

Some years ago I was working with a company developing an aquarium fertilizer. When we had the prototype ready, I prepared 5 extra high light/Co2 planted tanks just to tried different combination of over-dozing of this product. I combined it with Po4, Kno3, Fe, etc looking for algae bloom.

I discovered that there is a relationship between certain imbalances and certain algae. On the other hand, when I tried the solution that the EI and other method propose, they just didn't work.

I also confirmed that when you just add KNo3, Po4 reach zero and GSA blooms. I discovered that under this water condition, other algae stop bloom or dies. I called it the generic Kno3 protocol, which is the main tool we are going to use with the MCI.

B. What exactly is the MCI?

The MCI was born as an algae control method.
I discovered that when Co2 and Light are high enough and you have an issue with algae, this is related to an imbalance between nutrients after uptaking.

There are very close relationships between them and it is easy to solve any algae issue when you understand how do they work. I use the concept imbalance because talking about excess or lack is incomplete. When you use the terms excess or lack, you are talking about a macro/micro nutrient without any relationship with nothing more.

Old school asserts that algae blooms because of excess of nutrients, Po4 mainly. The EI asserts that the lack of nutrients is the cause of algae. Non of them are entirely wrong. Some times is a lack, other times is an excess, depends.

This is not important the combination of macros/micros we prepare on the fert bottle, the real important thing is the plant uptake and what is left in water.

The fertilizing approach of the MCI use algae to find out uptakes and propose to develop a custom fertilizing for each aquarium.

It is impossible to standardize a fertilizing regime. Light and Co2 are too overestimated, the main variable is the plants combination. There are some plants with priority uptake of Po4, No3, Fe, Ca, etc but most of them have no special needs.

For example, glossostigma elatinoides has a priority No3 uptaking. It means that if you don't add enough Kno3 you will probably have problems with cianobacteria. If you have a meadow of marsilea crenata and you don't add enough Po4 you will have issues with GSA. Anubias and microsorums are Po4 priority consumers plants too.

The idea behind the MCI is that if we have enough Co2 and light we can use the plants as the aquarium filter and we can induce chemistry changes that helps us to have an algae free aquarium at the same time we can have a proper/high grow rate. In some cases, for example, an aquarium with discus, we should chose Po4 priority consumers plants like marsilea crenata in order to look for a long term balance.

The MCI starts working with Kno3, low Fe (0.1 ppm) and no Po4 / potassium sulfate adding. But this is only a start, algae will tell you if you need to add Po4 and how much. I will explain it properly later.

If you come from the PPS or EI, before you start using the MCI you should decrease the amount of Po4 and Fe in your water, otherwise, the Kno3 generic protocol will take several weeks to produce Po4 zero and the plants will suffer a lot for lack of micros/Fe, etc.

C. Methodology

The method I proporse works only under certain light/water/plants/Co2 conditions. For this reason I will explain it properly.

Even when you look for algae info you can find a lot of possible causes for each of them (excess of water flow, excess of light, etc), I will focus in the key variable. The one that you change and the problem is solved.

Sometime the problem is the tap water chemistry. For this reason I will dedicate one chapter to explain the most common issues.

It's very important that you don't mix methods and if you forget all that you know, better. I found out that some of the knowledge we have is incomplete, wrong or just an improper interpretation of facts or experiments or papers.

I believe that the misunderstanding about algae is related to the use by analogy of hydroponic and terrestian plant cultivating knowledge. Algae doesn't exist out of water, so they don't even have to think about them. Plants are quite flexible about uptaking. No matter which fertilizing method you chose, they will be more or less ok. However, algae can show up and bad theory usually is responsible.

For example, everybody read about the Ca:Mg 4:1 ratio. This is a ratio from terrestian studies. Under the water this ratio produces several problems related to algae. The ratio that works better is exactly the opposite 1:4.

K is also an issue. The K is needed, no doubt, but more isn't better under the water. If you add too much K, the No3 can reach zero and you will be in troubles.

My basic idea is to discover the underwater rules, usually they are different, so, all the "scientific knowledge" from over the water became useless, problematic or open to debate. But there is not anything at all we can assert that it is a scientific fact unquestionable. I have tested by my self the rules you know from other methods, I confirmed some of them, I refuted many of them. Sometimes, with the same facts, I made a different interpretation that works better. But I never try to force the facts when an assert is not working. An assert that doesn't works should be abandoned because is bad theory.


When there is a balance in the aquarium, plants grow properly and you have no algae. You can reach this goal with any fertilizing method.

Unfortunately we deal with a dynamic balance that involves many factors over which we have more uncertainties than certainties. In this sense I think that the best way to understand our situation is with an analogy: a blind man that moves up the sidewalk with his cane. If this is his first time walking down that path, there are few things he can say for sure. The blind man knows that the street is on his right and the wall is on his left. But the fact is that he has no idea about how high are the building and it makes no sense to even try to find it out. For practical purposes, this person can go blind groping the ground with his cane until he finds the wall on his left and from there he can start walking and reach his destination without getting lost because although he lacks the ability to see, he can use the wall as a guideline.

In the aquarium we have a whole series of dynamic variables that we don't know but, as the blind man, we can choose between the wall and the street. In my opinion, and this is strictly arbitrary, the wall, the safety, are the GSA.

Thus, our target using the "Method of Controlled Imbalance" won't be having GSA but, instead, generate an dynamic equilibrium in which we can predict what will be the possible imbalance we may have. The idea is to generate a water chemistry close to GSA because the correction is as simple as safe for health and aesthetics of our aquarium.

Even this idea can sound a little weird for you, the fact is that all the fertilizing methods had a tendency to a certain water chemistry but they don't realize it. The EI, for example, has a tendency to Green Dust (an imbalance related to an improper Ca:Mg ratio plus too much Po4).

However, what happens is any unexpected imbalance occurs and other algae blooms?
There are some possible answers. Looking for re-establishing the balance as an immediate goal doesn't work.
Adding more fertilizing neither, only sometimes.

Following the blind man analogy, we should look for the GSA because when we reach it, we know where we are in the same way that finding the wall with the cane. A GSA friendly water chemistry is a desert for other algae and GSA is easy to remove adding a small daily amounts of Po4 (Po4 protocol).

The advantages of this methodological approach are manifold. First, like the blind groping the wall, the number of variables at play are endless but those on which we work are extremely limited which allows us an easily interact with them.


The MDC uses the plants as a catalyst for nearly any imbalance that occurs in the aquarium. Because there are so many variables involved, ranging from water quality, the combination of plants, fish, light, among others, I will try to standardize certain basic requirements without which it becomes difficult to maintain a healthy aquarium.

In this sense, this method assumes a light of at least 4 watt per gallon, Co2 between 25 to 35 ppm and that there are enough fast-growing plants (with only echinodorus this system does not work) .

1. Lighting. Generalities

When I propose to use the gallon/watts rule we are being as inaccurate as clear. There are many other ways to calculate lighting, lummens, pars, etc. I believe that the "accuracy" about light is just a delusion. There are too many variables in play and the subject becomes too difficult to understand.

For this reason, I am going to propose the gallon/watts rules with some corrective in order to look for more accuracy without losing clarity.

Overall, it says that the plants require at least 2 watts/g and in fact this should be read as it is the bare minimum to survive and grow for low requirements plants. However, our goal is a bit more ambitious because I want to induce a metabolism working at a 100% rate, which is why we recommend 4 w / g as a minimum. However, the feedback from the last two years it emerged that many people have successfully used this system with less illuminated aquariums (up to 0.3 watt / g). Anyway, we recommend to improve the lighting.

As I anticipated, this rule has some simple corrections:
1) The watt/g rule only works in aquariums up to 18 inches high. To set the height of the tank, measure the height of the aquarium glass (raw height) and not the clear height (height of the water column). TLD have little penetration in the water, if we don't use this corrective we can make the mistake of believing to have proper light with a deep aquarium. In cases of deep tanks, then we recommend the use of HQI.

2) In the front of the aquarium you should use PLLS in order to provide proper light to plant on the bottom like glossostigma elatinoides, echinodorus tenellus, etc. The advantage about PLL is that you have twice or three times more light in the same space.

3) The third correction is about light quality. We usually recommend to use, from the back to the front, grolux, 842, 954. The meadow plants (glosso, HC, etc) requires quantity instead of light quality. For this reason you can use 865 instead of 954 or HQI.

2. Water quality

Initially, the MCI didn't have this chapter but from the feedback came the need to give this subject its own space. I never underestimate its importance but I was aware of the enormous variety of chemical composition that we have throughout the world and I preferred not to generalize. The feedback has allowed me to identify specific problem cases witch I will describe briefly in this chapter.

a. One of the most frequents issues is related to overpopulation. Excess of fish, shrimp or melanoides may produce enough ammonia to produce Green String Algae. In this case, the tests may have a false negative, they aren't reliable because they read only the ammonia that algae didn't uptake.

To reduce the population is essential. Sometimes, increasing the biological filtration helps in long terms.

The use of zeolite is the best option. Usually this is commercialized as ammonia remover to add to the filter. There are other products that produce the same effect.

b. From the feedback and my own experience when I was in Annapolis, I discovered that usually the ammonia comes with the tap water. To test the tap water before every water change is a good idea when the aquarium is still "young" and without enough plants.

c. There are some places where the tap water is hard and with a natural imbalance related to Ca carbonate. Barcelona is one of this cases, Brooklyn another. In this cases we are going to deal with two problems. A high KH interferences with Co2 dissolution. And too much Ca produces a fertile environment for specific red algae (see the algae chapter).

An obvious solution is to use 50% of RO or destilled water/50% tap water with the water change.

d. Pollution is an issue and it is not going to get better. Many areas of Mexico, Brazil and Buenos Aires state (argentina) have problems with levels of No3 over 45 ppm in the tap water. A good quality water shouldn't have more that 10 ppm.
If your water has this problem there are some different options.

The most obvious is to use Ro water.

A second option is to use rain water and to blend it with the tap water.

A third option, if you have enough space, is to have a water reservoir with emerged potus.

The bases of the MCI is the use of Kno3. In those cases we can't do it.
Potasium sulphate is an option. Potassium carbonate or bicarbonate another.
But we should forget the usual recommendation about how much to add.
If the use of only Kno3 is so stable, then we should use this pragmatic rule. The NPK ratio in the Kno3 is 1/0/0,5 So, if we have 40 ppm of No3, we should add half of this amount of K, it means 20 ppm.

e. The tap water may also contains an excess of Po4. This happens when they filter the water and they add polifosfates to protect the filters. This happens when the water comes from the sea or it naturally contain some kind of poison in low levels like arsenic. This is the case of the tap water in NYC. It contains 3 ppm of Po4.

The best if to use RO water.

Even this water is complicated, if you chose plants properly you can have easily an stable aquarium. If you have a meadow of marsilea crenata and tap water cames with 3 ppm of Po4, then you probably will have enough Po4 to feed them. If you have some GSA anyway, then you should add a little bit of extra Po4, I explain it properly in the fertilizing chapter. I had an aquarium with a meadow of marsilea crenata and they uptake 4 to 5 ppm of Po4 weekly.
Anubias, microsorums and cryptos are a good choice too.

f. Sometimes you water is really complicated. You can have an imbalance related to Ca and Po4 at the same time. The NYC's is like this. GDA will be an issue and the EI theory about it just doesn't work. I will explain in the algae control chapter how to deal with this issue.

g. Sometimes tap water has too much sulfur. In this cases, if you add potassium sulfate you will have problems with some specific algae. Using 50% of RO water and only Kno3 instead of potasium sulfate solves this issue.

h. I read at the NY Times sometime ago about that the tap water in the states may contains over 60.000 different chemistry pollution and the law that rules the subject only takes cares of the most obvious issues likes the excess of No3. So, a RO filter is a good investment, not only for you fish and plant.

3. CO2

There is no need to explain how important is Co2, so I will deal only with the problematic topics.

There are charts to establish the level of Co2 in water that uses Ph and Kh. PPS recommends it. It's a mistake. The accuracy is so low that the ph/kh charts are useless, in fact, they are an obstacle. In my personal experience, this charts are useful only to help a beginner to understand that he has no enough Co2 only when the lack is humongous.

In fact, the main problem with this sort of charts is that you may think that you have enough Co2 when you don't.

The drop checkers has the same problem.

Electronic devices aren't magic, if we calibrate them improperly the Co2 will be low anyway. Devices like the Milwaukee uses Ph to stop Co2 injection. The most comfortable way to calibrate it is using the ph/kh chart and this is a mistake.

I used laboratory quality (no standart aquarium brands) Co2 test and I compare it to the charts and shrimp behavior. According with the charts my aquarium had 90 ppm of Co2 but fish and shrimp were perfect. But Co2 test read 25 ppm.

I believe that the best option is to use shrimp as bioindicator. I propose shimp because they are more sensitive that fish. At real 40 ppm of Co2 they start behaving weird: they try to escape. So, the procedure I propose is to spend one morning watching what is going on with the aquarium and every 30 minutes to increase a little bit the Co2 until shimp get upset. Then we turn on the air pump or any devices to oxygenate the water and we calibrate the Co2 with the 30 minutes previous doze. This is the real limit of Co2 your plants can uptake without risking your fish and shrimp.

If you have an aquarium with shrimp, then I suggest that when you arrive to the limit, you calibrate the Co2 with the 90 minutes previous doze and you compensate this range with Excell.

For example, you add 1 bubble per second, after 30 minutes you increase it to 2 bubbles per second and so on. When you add 4 bubbles per second shrimp behaves weird. Then you oxygenate the water and calibrate the Co2 in 3 bubbles per second.
If you are using a milwakee, you calibrate the PH a little bit higher.

However, there is a false positive. If you have discus and the have parasites in their branques they will be brathing in the surface even with low levels of Co2. The damage that the parasites produce in their branques is permanent but you can stop that the damage get worst.

Some tips from feedback:
- The distribution of the Co2 is as important as its dissolution in water.
- The crystal Co2 diffuser needs of a small power head to distribute the micro bubbles.
- The Co2 should pass by the prop of the power head instead of the ventury.
- The crystal Co2 diffuser usually works better in small aquariums.
- If you nano is too small for the smallest power head, you can tune it in order tu reduce the water flow like this:

In medium and big tanks we should use a sistem like this one connected to a strong 500 gallon/h power head:


To change 50% of the water weekly helps a lot to prevent algae.

IV. Fertilizing approach of the MCI

The MCI is a fertilizing and algae control method. Even it was born as a algae control method, soon its potential about fertilizing was obvious. Other fertilizing methods just pretend that algae doesn't exist and they don't take any responsibility about them. I believe that algae and fertilizing are two faces of the same coin. Algae give us feedback about how are we doing. If there is something wrong they bloom. No matter which fertilizing method you think you are using, as soon as you have some experience you develop your own method even if you don't realize it. But sometimes there are recurrent issues you can't solve, this is a feedback you should listen at. Sometimes you are the problem, sometimes the problem is that you are using bad theory. I mean for bad theory, an idea that doesn't work and because of that it should be abandoned instead of inventing pseudo scientific explanation when this is still not working. GDA is the best example. Even there is a very nice explanation about the cycle of living of this algae, the solution proposed (waiting) is … how to say it? … a confesion that the author has no idea about how to deal with it. But this is not the proper chapter to explain this, lets deal with the fertilizing.

1. Generalities

About micros and Fe, if you add 3 times more tan what your plants are uptaking you will have issues with red algae is we assume that your tank full fits the prerequisites I describe before.

About calcium chloride, even small doze may burn microsorum leaves. For this reason I don't recommend to use it.

The base of the MCI is the fertilizing with Kno3, not only Kno3, this is just a begging. The doze I recommend as a beginning for beginners is 1 gram every 50 gallons per week. The idea is to look for the real uptake of your tank, we are going to use the generic Kno3 protocol for that. It consist in adding this doze every day until you reach GSA. Then, the amount of Kno3 you added is the weekly amount of Kno3 you are going to use in future in order to have a water chemistry close to GSA.

About phosfate, as a beginning, I recommend not to use it right now. However, the doze I will use for the Po4 protocol is 1 gram every 500 gallon.

About dozing, the electronic scales are so cheap in the states that I don't find any excuse to avoid buying one.

b. Preliminary clarification

When we talk about weekly doze, you should add it every day. If you can't, at leas to divide it in three times is ok.

If I don't specify it, I always mean weekly doze.

Use the Fertilator for adding iron and Po4!!!! Don't take any attention to the doze propose by the manufacturer.

If you have HQI, then the Kno3 weekly uptake is 4 times higher. The starting dozing should be 4 gram every 50 gallons if you have enough plants.

2. Advance fertilizing

a) Kno3 & Po4

It continues...

· Registered
270 Posts
Re: Method of controlled imbalances and gda...

a) Kno3 y Po4

The generic protocol of Kno3 will be the main tool for algae control. We are going to use it for finding out the real uptake of No3 of our aquarium.

The generic Kno3 protocol:

1. First day 50% water change.
2. Stop fertilizing at all.
3. Add daily 1 gram od Kno3 every 50 gallons until you reach GSA.
4. As soon as you reach it or on the seventh day, 50% water change.
5. If GSA didn't bloom the first week, after the water change ad double the amount of Kno3 during this week.

In the fertilizing approach, this protocol works like this:
You add Kno3 every day, let's suppose you reach GSA the 3erd day in a 50 gallon tank. Then the weekly doze of Kno3 will be 3 grams divided in seven days.

If your aquarium is really healthy, the remaining ammount of Kno3 in the water should be low. If the No3 raises, this means that you are having problems related to Co2, KH, lack of light, overpopulation, bad tap water$ quality, etc. In this cases you should check the prerequisites out.

About Po4, you should be asking why I "restrict" Po4. Well, a healthy aquarium has a normal tendency to No3 lacks and excess of Po4. For this reason I suggest to listen to your aquarium and to add Po4 only if you need it. Green Spot Algae and pigmy leaf and syntoms of a real lack of Po4. On the other hand, we know that microsorums, anubias and marsilea crenata consumes a lot of Po4, in this cases we know we may need it.

And I would like to clarify this subject. If we add more it doesn't mean that plants will uptake more. If we are adding too much we are confesing that we have no idea how much we need. I look for efficiency.

I know probably think about I am limiting resources but I believe that this concept from Hydrophonic cannot be use just without any tune up in submersed crops. The reason is simple, we are not dealing only with plant grow rate, we have to deal with algae too. So the idea behind the MCI is not to limite anything, instead I am looking for efficiency. I made a living about submersed aquarium plants cultivating and I had great grow rate with zero algae. Algae for me meant bankruptcy, simply like that.

In fact, I am limitating resourses but not Po4, I limite K. I don't want that No3 reach zero, if we add too much K we can achieve this anti goal.

And the main idea is that there are plants with priority consumptions. With this concept I mean that only some plants uptakes a lot of a specific macro and this plants will define the fertilizing.

If we need to add Po4 because we have some plants that demand it we have two choices:

1. There may not be evidence of lack of Po4 like GSA. This happends when we have plants with priority consumption but not enough to alter significantly the water chemistry. In this case we can add a little bit of Po4 over the leaves with a syringe without needle. The doze may be insignificant in ppms but enough if we take care about uptaking, then it can be more than enough.
2. The second scenario is when we actually have GSA after stop adding Po4. In that case we shoulf use the Po4 protocol to find out the real uptaking of this macro. The Po4 protocol (Algae control approach: against GSA) (Fertilizing approach: Po4 consuming finder) is the following:

1. First day 50% water change.
2. Keep adding Kno3.
3. Clean the glases of GSA daily.
4. Add daily 1 gram of Po4 every 500 gallons until GSA stops appears.
5. As soon as you reach this point or on the seventh day, 50% water change.
6. If GSA didn't stop bloom the first week, after the water change ad double the amount of PO4 during the second week and so on.

Once we reach the point where GSA stop blooms, then we use this weekly ammount of Po4 as the weekly fertilizing of Po4. If it took three weeks to find out this point, you only use the last week amount, you don't add the 3 weeks amount.

b) Ca y Mg

The 4:1 ratio Ca:Mg cannot be sucesfully use under water. When there is too much Po4 in the water and you have an imbalance in the Ca:Mg ratio, you will have GDA. In my experience, if you add this macros, the ratio should be the opposite 1:4 Ca:Mg. The inmediate consequence of this idea is that you can't add too much Ca because Mg cannot be added in large amounts.
We can find out how much Ca:Mg we need in the same way I propose to do it with No3 and Po4. However, I sugest you better wait a little more if you are a beginner.

The MG protocol is:

1. First day 50% water change.
2. Stop fertilizing at all.
3. Add 0.3 ppm of Mg daily until the algae ".3. RODOPHYTAS SP. 3" blooms.
4. Then use the specific protocol for this algae you will find at the algae control chapter.

With this simple steps you will know how much Mg you need. About Ca, just add 25% of the Mg.

This is no necessary to reach this algae, rotalla wallichi can also be use as a bioindicator because it melts when there is too much Mg.

Rotala Macranta is a Ca priority consumer plant, so it will alter the Ca consumption of the aquarium. We can assert the same about ammania gracilis, if this plants get blackish that is a syntom of lack of Ca.

The Ca:Mg ratio I suggest is a generallization. Priority consumers plants always alter this kind of rules, but using the steps I mentiones and the algae as bioindicators, as the blind man with his cane, you can fin the balance of your aquarium.

I don't like to use calcium chloridre because it can burn microsorum leaves. Usually with water changes you add enough Ca. Other option if you have soft water with low kh is to use aragonite in your filter. It should be enough for standar requirements plants.

You know when you have an imbalance related to Ca because you will have algae rodophyta sp.2 (look for the picture at the algae control chapter) or, if you also have at the same time an imbalance related to Po4, then you will have an issue with GD.

c) Potasio

One of the special features of the MCI is that I don't recomend the use of potassium sulfate. There are some reasons.

The first one is that if you add this macro, the No3 will be uptaken and as soon as you reach zero you will have algae issues. The main goal I think is to avoid this situation. All the idea behind the MCI is to have a stable water chemistry where we know we are always close to GSA. If we add K this stability desapears.

On the other hand, it is better to do not add sulfur when we can avoid it. Bacteria oxidation may produce sulfuric acid. Of couse, if you add a lot of Fe you alter the redox ratio and this problem is neutralized but is more simple just to limite the adition of sulfur.

If you have hard water, you probably already have more that enough sulfur and adding more with the fertilizing may produce Grey Long Hair Algae (See algae control chapter).

K is needed, no doubt. But in my experience, with the low K we add with Kno3 is more that enough. If my asser is wrong, then microsrums pteropus shoul became black.

Hygrophila polisperma is a plant that consumes priority K. I have read that it is propose to be use as a bioindicator of the lack of K. This is a mistake, the uptaking of K with this plant in your aquarium becomes bulky.

You can put this plant just with water and potassium sulfate and it will grow well.

It continues...

· Registered
270 Posts
Discussion Starter · #3 ·
Re: Method of controlled imbalances and gda...

d) Ca, K y Sodium carbonates

There is a dificul solution issue about adding carbonate to the water of a planted aquarium. It almost an intuitive assert to add potassium of calcium carbonate or bicarbonate.
However, we shouldn't take attention to the total amount of K we are adding to the water. If we add potassium phosphate, nitrate and carbonate or bicarbonate, we will can easily be adding like 50 ppm of K. If we also add potassium sulphate, then the amount of K is too high. K by it self is not an issue like iron that can became poisonus in high dozes but it can produce that the No3 reach zero and that would be a problem.

If we dont want to add so much K, then the solution is to combine Cacium, sodium and potassium carbonates/bicarbonates in order to keep all of them in acceptable rates.

As I already explain in the Ca/Mg chapter, we should be carefull with the amount of Ca we add if we don't want to have issues with red algae or GD.
On the other hand, discus an apistos are sensitive to Ca.

The reason for adding carbonates to the water is related to avoid a breakdown of the buffer that allow the PH to fall to much.
I was born in Buenos Aires City, in Argentina. We live in just besides the De La Plata River wich borns in the Mato Groso swamps in Brazil. The tap water has 1.5 kh and barely no Ca. I never had problems with this myth about the breackdown of the buffer. Even the PH can fall, this is not a never ending fall. Only fish from hard water and high ph have serious problems. Botia macracanta is one of them.

I am not suggesting to have a 5.5 ph with our fish, I am just triyng to explain that this is not such a big deal.

We have this very soft water and hobbist have successfully been using aragonite for decades to avoid this buffer breakdown. Aragonite, coral sand, is thicker than the standar calcium carbonate we can buy. The advantage of this is that the water won't become white and as soon as its low water dissolving properties, the Co2 will dissolve it slowly when this is need and no more.

We only need a small amount of aragonite in our filter.

e) Fe

The MCI Works with only 0.1 ppm of Fe per week.

The PPS and the EI uses higher levels of Fe. Fe reduces the redox potential and It could be useful if you have too much sulfur in your water or it is pollutioned. On the other hand, if you have both, Po4 and Fe high, they will become iron phosphate.

There is a lot of debate about if plants can uptake it or not. It doesn't make any difference. You can know how much Fe are your plants uptaking if you like adding 0.025 a day until you get algae. I believe that this is not necessary, but you can do it if you feel like. The algae that will bloom for Iron can be stoped with the Kno3 generic protocol but you will need gluta to eliminate them.

However, I believe that the best is to add Po4 and Fe in alternating days. In my experience, 0.1 ppm of Fe is enough. Anyway, your plants will tell you if you really need more.

I know that it is a fact that you can have higher levels of Fe in your tanks with no algae, but I also know that this is less stable and there is no need for that. Plants will not start starving if you add Fe in a more efficiently way.

But It is all about to focus, don't mix method. You can add less Fe only if you add less Po4. As I explain before, it is all about imbalances instead of lack or excess.


· Registered
270 Posts
Discussion Starter · #4 · (Edited)
Re: Method of controlled imbalances and gda...


In this chapter I will describe the protocols (steps) I have sucesfully use to imbalance the aquarium looking for GSA as a first step, and loking for an balance later with no algae at all.



This is not very clear why this alage blooms. In my personal experience, it always blooms when the Kno3 and Po4 levels where to high together. However, seems that this is not the only situation where it can bloom. GW also is common in new aquariums, we can speculate that nitrite may also be a nutrient that this algae use.
Water changes don't solve anything, usually it is worst.
To avoid GW the best is to start a new aquarium with a lot of fast growing plants, not necesaryly the definitive you want to have.

You can solve it using for time the doze of Tetra Baktozym.

An UV filter is the best option. Make a 50% water change before you start using it and at the 7th day. Stop fertilizing at all.


This algae is related to ammonia. Please read about it at the water quality chapter in order to identify why you have ammonia un your aquarium.


1. First day, 50% water change. Check that the water you are adding is ammonia free.
2. Don't decrease the light.
3. Check the Co2 levels, don't assume it is ok.
4. Add just over the algae with syringe without needle 10 ml/25 gallon of hydrogen peroxide. Gluta / Excell is a good option. However, this products only solves the syntom.
5. Stop fertilizing at all.
6. Add 1 gram ok kno3 every 50 gallons daily.
7. 50% water change at the 7th day.
If you have enough shrimp they can easily clean this algae but they don't solve the imbalance that caused it. 4 shimp per gallon can clean a tank in two days. This is an easy solution if you already have them or if they are cheap. Where I live a bag with 200 of them cost like 2 dollars, they are used as live food.


I had this algae between I sold my old canister and I received the new one. The aquarium has a lot of echinodorus and just a few fast growing plants. As soon as the new filter has a week working and I add more plants, this algae desapears.


GSA is related to an imbalance between Po4 and No3. Essentially there is no Po4.


1. First day 50% water change.
2. Keep adding Kno3.
3. Clean the glasses of GSA daily.
4. Add daily 1 gram of Po4 every 500 gallons until GSA stops appears.
5. As soon as you reach this point or on the seventh day, 50% water change.
6. If GSA didn't stop bloom the first week, after the water change ad double the amount of Kno3 during the second week and so on.


This algae is related to an imbalance between light and Co2.
You should check that the Co2 is enough. Read the Co2 chapter to find out out toi reach the maximum you can add without risking you fauna. If there is no way to add more Co2, the you should decrease the light. This is unsuall and only happens when you use natural ligh in summer time.
You can use Excell to kill this algae, 4 times the recommended doze.
If you have a shrimp tank and you don't want to risk them adding more Co2, you should compensate it usiang Excell and Co2.
Riccia, Egeria densa and hemianthus micrantemoides suffer a lot with an Excell overdoze.
1. Check Co2 level.
2. Use the Kno3 generic protocol
3. Add 4 times the recommended doze for Excell


Cianobacter is related to an imbalance between No3 and Po4. Always means that there is too much Po4, it can happends because there isn't No3.

If you have discus the issue probably is too much Po4.
If the aquarium has a meadow or glossostigma elatinoides then the problem probably is the lack of No3.

Cianobacter can be kill in the same way than bacteria. You can add just over the algae with syringe without needle 10 ml/25 gallon of hydrogen peroxide once a day. Erythromycin can be use only when you have too much ciano.


Small amounts of ciano, probably caused because lack of No3. This usually happens when you have glossostigma elatinoides or a lot of fast growing plants.:

1. Use the Kno3 generic protocol.
2. Vacuum the cianobacter or use the hydrogen peroxide.


1. Use the Kno3 generic protocol but adding double the amount of Kno3.
2. Black out the tank for 3 days.
3. After the 3 days, star again the Kno3 generic protocol with the standard amount of Kno3 until you reach GSA.


1. Use the Kno3 generic protocol but adding double the amount of Kno3.
2. Black out the tank for 3 days.
3. Add 500 mg of erythromycin every 25 gallons once a day.
4. After the 3 days, star again the Kno3 generic protocol with the standard amount of Kno3 until you reach GSA.


There is a lot of confusión about this algae. The EI suggest that you should wait the life cycle of this algae ends (3 weeks).
However, a friend of mine waited for 6 months, the picture is from his tank.
I tested the water and I discovered a complex imbalance related to1) Ca: mg, too much Ca and 2) No3:po4, too much Po4.
Three days later after we worked out on this imbalances the problem was solved.


1. Use the Kno3 generic protocol plus:
2. Clean the glasses every day until GDA doesn't appears anymore.
3. In future, you should use a Ca:Mg ratio of 1:4.
4. If you add Po4, read the fertilizing chapter about Po4.
5. Read the water quality chapter about excess of Po4 and Ca in tap water.


This algae is related to an excess of Fe.

1. Use the Kno3 generic protocol plus:
2. add just over the algae with syringe without needle 10 ml/25 gallon of hydrogen peroxide once a day. Excell can be use too, 4 time the recommended doze.
3. In future, you should add 1/3 of the Fe you were using.


This algae is related to a complex imbalance where where there is too much Ca in relation to Mg and there is an excess of Fe too.

1. Use the Kno3 generic protocol plus:
2. add just over the algae with syringe without needle 10 ml/25 gallon of hydrogen peroxide once a day. Excell can be use too, 4 time the recommended doze.
3. In future, you should add 1/3 of the Fe you were using.
4. In future, change the Ca:mg ratio. Please read the fertilizing chapter about Ca:Mg.


This algae is related to an imbalance between Ca: Mg where there is too much Mg.
If you have marble in you tank, you should remove it.

1. Use the Kno3 generic protocol plus:
2. In future, reduce the Mg you are adding.


Lack of Co2 and Ca is related to this algae. Sometimes a high KH is the cause.

1. Use the Kno3 generic protocol plus:
2. Check kh, eventually, reduce KH using RO water.
3. Check Co2. Read the chapter about Co2.


This algae is related to an imbalance between No3:po4 where is an excess of Po4 and lack of Co2.

1. Use the Kno3 generic protocol plus:
2. Check kh, eventually, reduce KH using RO water.
3. Check Co2. Read the chapter about Co2.
4. Stop adding Po4, read about Po4 at the fertilizing chapter.


Increase your light!!!!!! Don't waste you time about silicates.


This algae is related to an excess of sulfur. It usually happens when your tap water already contains too much sulfur.

1. Use the Kno3 generic protocol plus:
2. Try to get a water analysis from the Water company.
3. Reduce or eliminate the use of sulfates (potasium, mg, etc)

G. Different algae at the same time

You should chose the worst and start working about it. Ciano is the worst always because it kills plants.
If you reach GSA this water chemistry will help you to start finding a long term balance.


I hope this work can be useful for you. I have been in this hobbie for 28 years. When I start using the most popular fertilizing methods and there were issues without a clear solution, I start looking for a way to enjoy of my aquarium without algae. This work is my feedback and the feedback of hundred of people who teach me a lot with his/her experiences during the last 5 year at
1 - 5 of 5 Posts
Not open for further replies.