Remineralization and Fertilization Salt Mix

[arcturus]

Hi! I would like to have some feedback from you on the following salt mixes and how to use them.

• The first is a (dry) mix to remineralize 100% RO water to ~6 dGH, ~1.5 dKH, ~10 ppm Mg, ~30 ppm Ca
• The second is a macro fertilizer mix: ~15 ppm NO3, ~2.5 PO4, ~20-30 K

These mixes are to be used in a tank with CO2 injection. The details are in the screenshots below, using the most excellent IFC calculator.

• The RO remineralizer uses KHCO3 to reach 1.5 dKH but this adds ~20 ppm K in the process. This means that +70% of the total weekly K will be dosed at once during water change.
• How should I dose the NPK fertilizer? Should I add ~70% of the NO3 and PO4 at water change together with the K, and then dose the remaining 30% split in 3 days of the week?
• Or should I dose 100% the macros at water change? Has anyone tried this in a tank with CO2 injection?
• The remineralizer can use chlorides only, sulphates only, or chlorides and sulphates. Regardless of the combination I will end up with a total ~100 ppm of Cl and/or SO4. What Cl and SO4 values should I target? The mix below has ~27 ppm Cl + ~90 ppm SO4.
• Will these mixes lead to excessive alkaline pH? We have <this other thread already discussing this topic>.

Many thanks!

Remineralizer mix


Macro Fertilizer mix

 

[plantnoobdude]

• Or should I dose 100% the macros at water change? Has anyone tried this in a tank with CO2 injection?

yes, it works well. add gh and macros at waterchange.

• The remineralizer can use chlorides only, sulphates only, or chlorides and sulphates. Regardless of the combination I will end up with a total ~100 ppm of Cl and/or SO4. What Cl and SO4 values should I target? The mix below has ~27 ppm Cl + ~90 ppm SO4.

i haven't seen any seen anything that suggests anions ratio matters much, i wouldn't care much and aslong as you have some of cl and so4, i wouldn't be too fussed.
also, do not mix calcium salts with any sulfate salts, it will precipitate.
if you see crinkly leaves with pronounced veins, suspect Mg deficiency. maybe up magnesium to 15ppm. calcium demand is fairly low in tanks so 30ppm should be a good number.
hygrophila polysperma with clear Magnesium deficiency

 

[arcturus]

yes, it works well. add gh and macros at waterchange.

i haven't seen any seen anything that suggests anions ratio matters much, i wouldn't care much and aslong as you have some of cl and so4, i wouldn't be too fussed.
also, do not mix calcium salts with any sulfate salts, it will precipitate.

Thanks for the reply! But if do not use calcium chloride + magnesium sulfate (or calcium sulfate + magnesium chloride) and use chlorides only or sulfates only, then I will end up with no SO4 or no Cl... since this is RO water, there is near zero SO4 and Cl. How to solve this?

 

[plantnoobdude]

Thanks for the reply! But if do not use calcium chloride + magnesium sulfate (or calcium sulfate + magnesium chloride) and use chlorides only or sulfates only, then I will end up with no SO4 or no Cl... since this is RO water, there is near zero SO4 and Cl. How to go solve this?

i meant just dont mix them in solution like your macros, in tank it will be fine. just dry dose and keep the salts separate.

 

[medlight]

a¿Alguien sabe de una relación entre Cl- y S?