Originally Posted by DiscusLoverJeff
Thank you Overstock, that is why I stopped using it and was told to use dry ferts instead. I have read some good threads on this topic.
I'd do the following for the tank assuming you have 120 W of T5 or more lighting, and fully planted:
3x a week
3/4 teaspoon KNO3
1/2 teaspoon KH2PO4
Traces, I'd likely make a stock solution, but dry is fine, maybe 1/4 tsp
Water change day: 1 Tablespoon of GH booster
So dose water change day everything, then the traces and N and P 2x more through the week.
The big issue with discus is CO2 CO2 and CO2 and O2 and O2 and O2.
Ferts have no effect I've ever been able to tell, and........unlike many offering advice about ferts and the discus, I've bred them under typical EI dosing while feeding the snot out of them(which is why they bred).
CO2(too much) and not enough O2(folks think discus hate current, and at the expense of good O2). Respiration is both O2 and CO2. VERY few aquarist measure O2, even though it's the more critical thing for the fish, particularly larger fish. Use the rule of thumb Hoppy suggested: just enough surface movement to not quite break the water's surface with turbulent flow.
This will provide a lot more wiggle room with CO2 dosing.
It might be easier for you do to do 40-50% 2x a week than one 70%, then you could likely just dose after each water change and not have to mess with dosing further.
Many breeders do this routine.
Hope this helps