Thanks to all for the notes. Here are more details:
No CO2, only 7-9mL Excel daily
I have 2x65w T5 for 10hrs/day
I will say that because I'm not dosing CO2, but am supplementing Excel, I'm not sure what exactly my EI amounts should be.
Someone suggested I should be dosing twice as much KNO3 as I am. Yes? No?
I would dose abut 1/4 EI if you use non CO2 Excel dosing.
IME/IMO, add a lot more plants.
You likely only need 1 of those bulbs, not both, so if you can turn one on for say 5 hours then off, then the other on for the last 5 hours, that would be best.
This is 100% CO2 related.
Excel will take a little time for the plants to bounce back, and that is reflected in your growth.
Since you are only doing 1/4 EI, you likely can reduce the water changes once things settle down to monthly.
Excel: dose this amount DAILY: 25 mls.