Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
It will probably take some math to figure out, but look up some dry fertilizer products like Miracle Gro, or Peters and see what the N-P-K numbers are, and what the sources of these nutrients are. I think Peters is 16-16-16, but it has been a LONG time since I used it.
Then see if you can relate it to the fertilizers you have.
If that does not work, then try this:
If you wanted to use the used aquarium water, then you would already have put a pinch of this per gallon and a smidge of that into the tank. So put that much of each in a gallon of water exactly the same as if the gallon of water was a nano tank that you are dry dosing, and water the plants with it once, then use tap water a couple of times, then water with that 'aquarium-like' water.
At that low rate you might be OK mixing iron and phosphate, but it is OK to make 2 bottles of 'aquarium-like' water. Then I would do this:
Day 1 use macros.
Day 2 tap water.
Day 3 micros.
Day 4 tap water.
The tap water is in there just in case the fertilizer blend is too strong. If things work that way, you can keep on that way, or make changes.
If you double the concentration, then you will have to blend tap water with it when you are ready to use it, 50% 'concentrated aquarium-like water' + 50% tap water.
If you quadruple the concentration you would mix 25% fertilizer + 75% tap water
...and so on.
Eventually you would reach a point where you are adding perhaps 1/4 cup of fertilizer to a gallon of water and using this maybe once a week? At this point I would not make a blend of phosphate and iron. They will precipitate at some point.