Aquatic life t5ho

It'd be higher end medium for sure, I'm not sure how great the reflectors on that fixture are.

If you're not wanting co2 I say go for it, adjust the height of the fixture if you need to. If you are injecting co2, I'd skip this and go for something nicer, maybe a 4 or more bulb fixture with good reflectors.

AquaticLife T5HO fixtures all have separate reflectors for each bulb, and are some of the best on the market right now. Because it's on a 40 gallon breeder it puts you into the high light category, with most T5HO systems if put on a 55 gallon tank even a single T5HO 6500k bulb in a AquaticLife is enough to give off enough PAR value to sustain a medium planted tank.

I would suggest using a hanging kit to suspend it around 8" to 12" above your tank so you don't risk the chance of giving the plants light burn. Also because it's high lighting co2 is a MUST in the tank, whether it's a co2 injection system, diy co2, or flourish excel.

If I were you I would just try and get the CO2 going as high as you can, of course not so high you cause your fish discomfort. You could try a drop checker, but they aren't always the most reliable.

I have a 40 gal long, and my bubble count is almost uncountable. I want to say 7-8 bps.