Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Always include the units when you report test results. Are the GH and KH in degrees?
pH in those colors seems to suggest about 8? Is that what it looks like to you?
Sporadic dosing may be part of the problem. Lets figure out some kind of schedule and stick to it for about 2 weeks, see what happens.
Very lightly planted, and most of the plants are not noted for being really fast growing or 'nitrate sponges'.
NO3 is high, perhaps from fish food?
Fish food is high in N, P and most traces. If the NO3 is high from fish food, then these other things are high, also.
Fish food is low in K, Fe, Ca, Mg
Water seems to have plenty of Ca, but not much Mg.
I would calibrate the NO3 test before relying on it too much, but if it is right, here is what I would do:
50% water change to reduce the NO3 and other things from fish food.
Dose potassium, chelated iron, carbon (excel or similar) and magnesium. You could dose very small amounts daily, or a bit more every other day. I would not spread out the dosing more than that, though. Make the conditions as close to stable as possible.
Do not dose N, P or traces (except for iron)
Try this regularly for 2 weeks and monitor test results and plant growth.
If the NO3 keeps going up repeat water changes as needed to keep it between 10-20ppm. This ought to keep the other nutrients from fish food in the right range, too.