Keep in mind when you do a
WC you want to test your water paras after the
WC and dose ferts accordingly. Simply doing a certain amount of
WC on a certain day of the week and doseing a certain amount of ferts every time is a disaster waiting to happen. If you over feed or lag a couple of days on a
WC. Phos, Nitra and Amon can get out of hand.
Do Phos and Nitra test every couple of days till you get an idea of how your tank is consuming nutrients (feeding more or less, adding/removing fish, early or late
WC's, changing
CO2 amounts, changing amount of lighting as well as, other variables can change a tank). Generally you want Phos/Nitra ratio at 1:10. Phos between .5-1 and Nitra between 5 and 10.
Seeing how you already have the intense lighting. Try toning it down a bit. Maybe on 3-4 hours, off 2-4, on 3-4, off for the night.
Seeing how your dosing dry ferts. I'm assuming your using Chuck Gadds calculator. If not, I strong suggest you go to his web site and download his calculator. Also, reread Rex Griggs
FAQ here on AA. Both of these gentlemen have been kind enough to share thier knowledge. Good luck