considerations for pre mixing CaNO3 + KH2P04 + K2SO4

[deeloke]

Dear chemistry gurus,

is it advisable to pre mix the following dry ferts (used to provide macro nutrients)?

- CaNO3 TO PROVIDE: Nitrogen (N) [with a little calcium]
- KH2P04 TO PROVIDE: Phosphorous (P) [with a little Potassium]
- K2SO4 TO PROVIDE: Potassium (K)

If so, should I use a preservative? Are there other considerations i should factor in when pre mixing these into a 2 liter bottle to be used over a 12 month period?

And is it possible to buy dry micro ferts in SG?

Regards,
Dee

[Fuzzy]

There are a few brands of dry micro ferts available locally. Seachem and Lushgro come to mind.

My chemistry is too rusty to tell you offhand if you can premix the listed macro nutrients into a single stable aqueous solution though...

[Navanod]

No can do. You'll end up with alot of white precipitations

[blue33]

For micro ferts you can consider "EasyLife", this is a good brand alot of people will miss it, Y618 is bringing in the bigger size bottle hardly seen on the market. Their macro is as good too.

[iewnuj]

Hmm, I pre-mix Seachem Nitrogen, Seachem Phosphate and Ferka Potassium into a bottle for easier dosing.

Is the composition/elements still intact when I pre mix it? Please tell me it is, I've been doing that for quite some time already!

However I don't see any precipitates in my pre-mix bottle, still a clear blue solution...

[Shadow]

precipitations happen because CaSO4 is insoluble

You can mix CaNO3 and K2SO4 to get KNO3, then mix KNO3 with KH2PO4
K2SO4 + Ca(NO3)2 -> 2KNO3 + CaSO4

Not sure Seachem Nitrogen, Seachem Phosphate and Ferka Potassium originally from, so precipitations may not happen

[atolylica]

Hi Shadow,

I'm mixing CaNO3, K2So4 and KH2PO4 into 1 solution and I get a layer of white precipitate at the bottom. Is that CaSO4 like you mentioned?

Can I still use the mix? I've been dosing it for the past week and my plants seem fine.

Appreciate your advice. Thanks.

[ole]

yeah, the white ppt should be CaSO4. if its me, i'll just still add the whole thing into the tank. CaSO4 should be very fine. so its okay to just let a small quantity to float around and settle at the bottom of the tank. If you want to maintain the pH around 7-8, the presence of CaSO4 (s) can act as buffer too. though might not be too effective.

point is, there's no harm in having a small quantity of CaSO4 in the tank. Since its in ppt state, it should also just do nothing. it's only if you want a very acidic tank (god knows why), then the CaSO4 will interfere with it.