PO4 - In experience, how much per week to dose?
After months of just assuming that my PO4 was at 4.0 and nothing I can do to control it, was proved wrong tonight and it is down to practically none (<.5). Since I have high NO3 (20-30ppm), I figure I need to maintain my PO4 at 2.0 or so.
I made a stock solution that raises the PO4 by .2 per ml.
I just raised the tank up to ~2.0ppm, but unsure how much to dose in my normal 3x per week dosings of macros (along with K and NO3).
I still plan on testing the PO4 continuously until I get it right, but in most other tanks what is the normal plant usage per week? I.e. should I expect it to drop back to .5ppm by next Tuesday, or will it slowly decrease over a long period of time.
And I do know that it is tank specific on the usage, so I am really just looking for a big-picture expectation to judge by.
Some quick facts: 40g's, 5wpg, 30ppm co2, ~25ppm NO3, 11 hour light cycle.
450g Planted Discus Tank - Work in Process!