[livingword26]

I just bought a pound of Macro Mix from Aquarium Fertilizers.com. It is made of equal parts MgSO4, KNO3, K2SO4, and KH2PO4. I used Chucks Calculator to try to get an Idea of what to dose, and, if I use a teaspoon per 10 gallons, I get 3.5 ppm Magnesium, 23 ppm Nitrate, 17 ppm Potassium, and 25 ppm Phosphate, respectively. Am I doing my math right? Isn't that a holy cow amount of phosphate in comparison?

 

[livingword26]

Anyone? This is a low light low tech tank, and I was planning on keeping my nitrates around 5 ppm anyway, but is having an equal amount of phosphates even usable, in the long run?

 

[Maryland Guppy]

That is an excessive amount of PO4.
Typical NO3 to PO4 ratio is 10:1
If all 4 compounds are all mixed together of equal amounts may not be such a good idea to purchase this.
No flexability in creating your solutions.

 

[livingword26]

Thats kind of what I thought. Unfortunately, I did't really do the math before I bought it. I have a phosphate test on the way to find out for sure.

 

[burr740]

Seen that before, no idea why they did equal parts n,p,k

 

[Seattle_Aquarist]

I just bought a pound of Macro Mix from Aquarium Fertilizers.com. It is made of equal parts MgSO4, KNO3, K2SO4, and KH2PO4. I used Chucks Calculator to try to get an Idea of what to dose, and, if I use a teaspoon per 10 gallons, I get 3.5 ppm Magnesium, 23 ppm Nitrate, 17 ppm Potassium, and 25 ppm Phosphate, respectively. Am I doing my math right? Isn't that a holy cow amount of phosphate in comparison?

Hi livingword26,

I believe you may have misread the how the Aquariumfertilizer.com Macro Mix is formulated. The mix is put together by weight not volume so the weight of the various chemicals need to be factored in. That said, I used the APC Fertilator to calculate the ppm for the various components of the mixture if 0.70 grams (weight measurement) of each component where added to a 10 gallon tank. Here are the results:

The results are different but still disturbing: the nitrate ppm is good; the potassium ppm is a just a little high; the magnesium ppm is fine; but the phosphate ppm is still five times (5X) higher than recommended. I did not compute if 2.8 total grams (4 X 0.70 grams) of the mix equals a 'teaspoon' but maybe someone with the mix and a gram scale can do the measurement.

If I were you I would suggest caution.

 

[livingword26]

Thank you for that calculator. I will use caution, and probably have to get some separate macros.

 

[houseofcards]

What is the reasoning for putting so much phosphate into the macro mix? Why would they do that? What you can do is pick up some KNO3 and just add it into the mix. This will bring the phosphate down to recommended levels?

 

[Doogy262]

Just curious are you buying the macro micro mix from Aquarium Fertilizers because I have been using it for two years and it consists of equal parts KNO3,K2SO4,Mgso4 and CSM+B I see no mention of KH2PO4
unless you have a different batch.

 

[livingword26]

Just curious are you buying the macro micro mix from Aquarium Fertilizers because I have been using it for two years and it consists of equal parts KNO3,K2SO4,Mgso4 and CSM+B I see no mention of KH2PO4
unless you have a different batch.

Thats MACRO MICRO MIX, it has no phosphate. I just wanted the MACRO MIX, because I am doing something else for micros.

 

[livingword26]

Well, I'm just going to use the macro mix for phosphate. In those small amounts, the other ferts are negligible. I just ordered some kno3 and ks204 from Nilog. My phosphate test got here today, and I have 10 ppm. Water change time.