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Old 02-16-2010, 06:57 AM   #1 (permalink)
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Default Method of Controlled Imbalances Summary



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...

Last edited by Christian_rubilar; 02-17-2010 at 06:17 AM..
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