Planted Tank Guru
Join Date: Jun 2004
Location: Baton Rouge, LA
I also have a 46G, 2x39W T5HO, good CO2, EI. I was having similar problems, until I realized that between EI and the fish food for a heavy stocking, my nitrates were peaking at 140ppm right before each weekly water change. Phosphates were reaching 30ppm as well. Way beyond any sane excess. It was also stunting plant growth. Cutting both out of my EI dosing, and replacing the potassium they'd normally provide with K2SO4, solved the completely and significantly improved plant growth. EI is not set in stone, it's meant to be adapted to these kinds of situations; and though it eliminates regular testing, it doesn't always eliminate the need for tests completely. If you suspect your fish load or feeding might be enough that this is an issue, break out a nitrate test kit and investigate.
Also, java fern doesn't grow well for me, in any tank or conditions. Neither does cabomba or hornwort. All "easy" plants. No idea why, but I've heard the same from other hobbyists; especially local ones. Maybe it's something in the tapwater. Not everyone will have equal success with every plant. Not worth getting frustrated over, try other plants.