What kind / brand of fertilizers are you using?
Osmo+ as root tabs, with iron twice a week, and API's plant food (easy grow? Something like that?) once a week. Getting nitrate and phosphate target ferts tomorrow in the mail. They are nonzero, and need to be higher.
How are you monitoring how much CO2 you are using?
I have CO2 drop. Keeping it right in the middle of the spectrum. I also have a bubble counter on my CO2 Art reg, but it is uncountable now, needing to saturate a 55gal tank.
What is the tank size and the exact lighting you have?
55gallon, standard. So, what, like 18" deep, mayhaps? I have, currently, a Fluval 3.0 Planted and a CurrentUSA Marine Orbit v1 to supplement the Fluval. However, I am in the market to upgrading the CurrentUSA to better help the Fluval (I'd like to touch on this topic, too).
How long are the lights on per day?
6 hours a day, after I just got done beating a green soup outbreak. Got a UV Filter and blacked out the tank for 3 and a half days, and now it's as clear as day!
What is your water source? Do you know the KH, GH and pH of the tank water?
My water source is from my house. PH is roughly about 7, off the top of my head (if I remember correctly). Maybe a hair under. I don't have the hardness readings, though. But it doesn't seem hard (based strictly on my skin not really drying out after a shower...so take that how you will lol)