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Re: Method of controlled imbalances and gda...

Christian,
I have VERY soft water where I am and add a GH booster that contains 4 parts Ca, 1 part Mg and a trace of (1/40th) Mn and also add alkaline booster by Seachem to raise KH.
What do you recommend as an appropriate ratio for the Ca, Mg and Mn?
Is my Mg content enough?
 

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Re: Method of controlled imbalances and gda...

It's better if you can change 50% water change weekly because this way you are adding Ca but it has nothing to do with reseting the tank.

Regards
I'm in the same boat as Newt, I have very soft water. I have to add in Ca, and Mg as well; there is virtually none in my tap water. I add Magnesium Sulphate and Calcium Sulphate for this.
 

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Discussion Starter · #68 · (Edited)
Re: Method of controlled imbalances and gda...

Christian,
I have VERY soft water where I am and add a GH booster that contains 4 parts Ca, 1 part Mg and a trace of (1/40th) Mn and also add alkaline booster by Seachem to raise KH.
What do you recommend as an appropriate ratio for the Ca, Mg and Mn?
Is my Mg content enough?
There doesn't exist proper ratios for Ca/Mg neither. It's the same critic I do to the 10.1.15 NPK ratio. Healthy plants and no algae will show you when you reach your own proper ratio. However, you need a start point, you can use this ratio you mentioned if you have plants like rotala macrandra or other that needs lots of Ca (I prefer to use the term "with priority consumption").

I posted the pictures of two algae, one related to an imbalance with Ca, the second related to an imbalance with MG. As I said, you can try any ratio you want and tune it up using algae and plant deficiency as bioindicators. It's the same than Kno3/Po4.

In my experience with very soft water, a better start point is an inverse relationship: 4 parts Mg and 1 part Ca.
Some years ago I worked with a company that develops custom fertilizers and they developed this one with Mg and no Ca. The agronomist in charge of that small company has a PHD about fertilizing and he was professor at the subject "fertilizing" at Buenos Aires agronomy University:



We had positive feedback for 3 years, so I am not speculating about the asserts I made.

I tried GH booster and it works well.

Anyway, I don't like to use calcium chloride because you can have problems with microsorums and young leaves of some plants can be burn. In the other hand, I think that Mg is more important.

About soft water, I used to live in Buenos Aires city, the tap water came from the Matto Grosso through the Parana River, so it was absolutely soft, 1.5 kh, no Ca little Mg. It's not big deal, you need to add Mg for sure and perhaps some Ca. I used aragonite in the filter and it was Ok with plants with no priority consumption of Ca. I also tried calcium nitrate and Calcium carbonate and they work ok.

Regards
 

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Discussion Starter · #69 ·
Re: Method of controlled imbalances and gda...

Thanks for this article/thread.
In fact, it is a debate, the original title was "debate: algae control & fertilizing method". We were debating for over a year at www.drpez.com. The version you can read in spanish nowadays is the result of that debate and the feedback of the users. The debate was never closed, and the article never finished because the idea is to continue it in order to improve the MCI every day.

Regards
 

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Discussion Starter · #72 · (Edited)
Re: Method of controlled imbalances and gda...

Algae came back. What did I do wrong?
Ok, after the 7th day water change, what did you do?

The main idea is to change the way you were fertilizing in order to find a balance in long terms.

GDA is related to an imbalance of Ca:Mg and Po4.

There are two ways to deal with the Ca imbalance.
1) You should reduce the dozing of Ca.
2) Or you should add more Mg.

As I wrote, I think that a better ratio es 4 parts Mg 1 part of Ca.

Regards
 

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Re: Method of controlled imbalances and gda...

Algae came back. What did I do wrong? I think I am too lazy for this method of algae control. I have to actually think. :yield:
What I did when I reached the point where the GDA was disappearing was to take a nitrate reading. It was ~20ppm (double of what I was keeping my tank at. I now keep my tank at 20ppm NO3 and I only have a little left on some Crypt and Java fern leaves

I'm working on the PO4 level to combat the GSA.
 

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Re: Method of controlled imbalances and gda...

Hello all,

I have GDA appear where I have to clean every couple of days. My water tests at 4 Kdh, 11 Gdh, Ph at 6.4 with 30 ppm CO2 (green drop checker-4 Kdh water). Water changes are about 30 % per week.

I just started adding 1 gram of kno3 (everyday), and stopped adding csm+b and k2hpo4 about a week ago. I probably will need to go to 2 grams per day next week. My nitrate readings don't quite reach 10 ppm.

I have no idea what the percentage is of calcium and magnesium in my 11 Gdh water. Is there anyway to make an educated guess as to how much magnesium I could add to counter act the possible calcium imbalance? I haven' t really checked to see if there are any freshwater magnesium test kits for a reasonable price. I live in Leesburg Virginia, 40 miles west of Washington DC for any expert familiar with this area. My tap water comes from the Potomac River, no I don't have three eyes yet.
 

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Re: Method of controlled imbalances and gda...

Ok, after the 7th day water change, what did you do?

The main idea is to change the way you were fertilizing in order to find a balance in long terms.

GDA is related to an imbalance of Ca:Mg and Po4.

There are two ways to deal with the Ca imbalance.
1) You should reduce the dozing of Ca.
2) Or you should add more Mg.

As I wrote, I think that a better ratio es 4 parts Mg 1 part of Ca.

Regards
Ahh, I got the Mg and Ca backwards. I put 4 parts Ca and 1 part Mg. I used the fertilator, but it doesn't help if you use the wrong ratio, huh? Okay. I'll try again.
 

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Re: Method of controlled imbalances and gda...

......
I have no idea what the percentage is of calcium and magnesium in my 11 Gdh water. Is there anyway to make an educated guess as to how much magnesium I could add to counter act the possible calcium imbalance? I haven' t really checked to see if there are any freshwater magnesium test kits for a reasonable price. I live in Leesburg Virginia, 40 miles west of Washington DC for any expert familiar with this area. My tap water comes from the Potomac River, no I don't have three eyes yet.
Call your local water department or board of health. You could alos ask a company that does water treatment for any manufacturing facilities in your town.
 

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Re: Method of controlled imbalances and gda...

So far so good. I just found out I only need 3/4 tsp of KNO3 per week. That's half of what I had been dosing. Now I'm working on Phosphates.

My poor plants look like they are suffering from lack of Potassium, so hopefully this won't take long and I can get them back to good health.

-Dave
 

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Discussion Starter · #80 · (Edited)
Re: Method of controlled imbalances and gda...

I have no idea what the percentage is of calcium and magnesium in my 11 Gdh water. Is there anyway to make an educated guess as to how much magnesium I could add to counter act the possible calcium imbalance? I haven' t really checked to see if there are any freshwater magnesium test kits for a reasonable price. I live in Leesburg Virginia, 40 miles west of Washington DC for any expert familiar with this area. My tap water comes from the Potomac River, no I don't have three eyes yet.
Well, I think that the best is to do what Newt said.

I can give you a few more ideas.

1) You don't need a Mg test. If you have a GH one then you just need a Ca test: GH - Ca = Mg

2) You can look for the Ca:Mg balance like a blind man with a walking stick. Do the same than the Kno3 protocol but with Mg. It means, clean every day GDA and add MG every day until GDA doesn't show up. Then, this is the amount of Mg you need. If the algae related to Mg appears, then the amount is 1/3 below that as the weekly fertilizing. (footnote: Hard water can be an issue for your fish, and Mg can be toxic in high levels, so you know your tank better than me and you can choose the best solution)

3) I think that the best you can do is to reduce Po4 to 0.2. GDA is an issue because you guys are used to add a lot of Po4 and Fe. For me it makes no sense and causes lot of problems. I explain you why:

The main idea behind the MCI is to reach efficiency. Think about this analogy: if you prepare lunch, is a sign of good feeding that a lot of food remains in the table? Is it a sign of starving that after lunch the table is empty? I don't think so. But this is the approach used with fertilizing.

I disagree about adding 1 or 2 ppm of Po4 because then, when you add Fe, they became FePO4 (iron phosphate) and both are not immediately available for plants. I read in a thread about this topic and there was an argument that asserts that plants can use them by the roots, but that approach makes no sense for me because then is better to use laterite blended with humus.

I propose to add the Po4 you need and no more. The same with Fe. And to add Po4 and Fe in different days, alternated. This way plants uptake immediately the Po4 and Fe.
So, how to know the ppms you should add? There are no rigid rules, you should find the needs of your aquarium.

Well, about Po4, GSA is a prompt bio indicator, plant deficiencies a late one. I had GSA adding 3 ppm of Po4 because I had a carpet of marsilea crenata that is a plant with priority consumption of Po4/ With 4 ppm GSA didn't show up anymore.

About Fe, I think that the best is to start with a low dosis like 0.1 ppm per week. And the day after, before adding Po4 it should be in zero. That's perfect. You can increase the dozing with two limits, the algae I relate with Fe excess and test measuring the day after.

This way you can deal with GDA without a Ro filter and without making Mg an issue.

Regards
 
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