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pps macro problem

4K views 6 replies 4 participants last post by  Seattle_Aquarist 
#1 ·
I just got my fertilizers yesterday and mixed up the solutions. I could find anything about how much caso4 to add but I've heard that calcium and magnesium requirements are about the same so I added the same amount of calcium as magnesium to the macro bottle and used reverse osmosis water instead of distilled. I left it overnight and it is a big clump of solids in the bottom and very little water on top. Can I still use this or do I need to start again. I have a 55 gallon tank and i made 2 litter solutions so by my calculations I would be throwing out a years worth of fertilizer which I would rather not do.

Thanks
nicole
 
#2 ·
Hello Nicole,

I'm puzzled as to why you used CaSO4. The Macro recipe calls for K2SO4, KNO3, KH2PO4, and MgSO4. I'm not a chemist, so I'm not sure if using CaSO4 would cause your clumping issue or not. However, when you say you have "a big clump of solids in the bottom and very little water on top", it makes me think that you put way too much of the ingredients. Did you measure everything out on a grams scale?

My guess is that unfortunately you probably aren't going to be able to use what you have already mixed up based on your description. I guess you could dilute the mix and use it to fertilize house or yard plants though.

Good luck.

Andy
 
#3 ·
Yes I used a scale and accuratly measured everything down to grams. I added calcium because the website I used said that caso4 was one of the nutrients required for pps but then it doesn't show anywhere how to dose it. I am very confused on this because even on this site it says calcium is a macro nutrient but its not included in the macro solutio and I don't see how I should be dosing for a 55g tank. Can anyone help me out with this?
 
#4 · (Edited)
Hi nikky119,

I used to do PPS-Pro dosing, maybe I can help. I used KNO3, KH2PO4, and K2SO4 in my macro solution. I also added 10 ml of Excel to my Macro solution to eliminate fungus growth.

Unless you have very soft water, chances are there is already sufficient calcium and possibly magnesium in your water. My water here in Seattle is extremely soft so I add sufficient Seachem Equilibrium to bring my dGH to 4.0 (which is the level recommended by Tom Barr). Thereafter, I only add additional Calcium and Magnesium to my aquarium when my GH level is low or if my plants showed signs that those nutrients were causing a deficiency. BTW, the ratio of Ca:Mg is about 4:1 (Seachem Equilibrium is 3.3:1). Here is an more thorough thread on the Ca:Mg ratio.
 
#5 ·
The precipitate is most likely a solid from the Ca2+ reacting with the H2PO4- to form some sort of Calcium phosphate species. (Phosphates in general are insoluble.) As Roy stated, unless you have very soft water and your plants are showing signs of deficiency, i'd just leave the CaSO4 out of the solution.
 
#6 ·
Thanks this makes more sense now I wish that was clearer on the website so I didn't spend money on ca. My water supply seems to be ranked in the middle number 48 out of 100 cities having 6.7 mg and 35 ca that in ppm. Would that be be enough ca? Also is the ca in water supplies unable for plants as I have read a number of post that say that even if you have mg in your water you should still dose because it's not in a usable form. If I need to dose ca should I dose it seperately from the macro dosing since it seems to be causing a clumping problem.

Thanks for all your help.
nicole
 
#7 ·
Hi nicole,

It does sound like you should have sufficient Ca and Mg available from your water. If it were me I would just make up a macro solution with the KNO3, K2SO4, and KH2PO4 and dose with that and see how things grow. A periodic water change should help to maintain enough Ca and Mg to avoid deficiencies.
 
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