I am going out of town for a while and I am having a neighbor assume responsibility for dosing the tanks.

I would like to combine all three macro's - NPK - in one vial to minimize the possibility of over or under dosing.

The pre-measured doses would then be added to the tank at the scheduled times.

Are there are any issues in combining the macro's together?

Regards,

PMD

I think the answer might depend on wich chemicals you are using.
I usually mix KNO3, KH2PO4, K2SO4, MGSO4, Seachem Flourish and Iron. I have put some though to figure if there would be any reaction, and excluding the Flourish"es", I couldn't figure any reaction. I also haven't found any information regarding reaction between these chemicals.

My experience: I have been preparing large quantities of mixed fertilizers for some time now and haven't noticed any difference from independent dosing. Apparently, no toxic side products as well, if this is your concern (based only on healthy fish and shrimp).

Regards,
Bode

EDIT:
Actually, it has been discussed that PO4 and Fe reacts and precipitate. Indeed I have some cloudness in my mix, but it disapeers quite quickly after added to the tank. Maybe I am losing Iron and PO4???
Source: PO4 and FE

You may mix all macro nutrients/GH etc together.

The Traces, the Fe etc, that should be added separately.

I will pre weigh/measure etc the NPK's and then leave a syringe for the Traces and a note saying add 5mls each time.

Have them add both at once to the tank, it's not likely many will visit every day to dose etc. The PO4 and Fe are much more dilute in the tank, so do not worry too much about it there.


Regards,
Tom Barr