Airstone(s) to help with BGA?
Hope someone can help me with my BGA issue. My tank's a 200 Gal plain gravel bottom. It is a low tech set up and i am currently dosing:
- 3% Glutaraldehyde, 10 ml daily
- KNO3, 1/5 tsp daily
The tank has only 128W of T8 on for 6hrs a day, but it gets a fair share of indirect sunlight... so far the only algae i am having trouble with is Bluegreen algae on some Ceratophylum submersum and echinodorus leaves, driftwood and on the substrate as a carpet (around the front and sides, there is no BGA on the back substrate). I do about a 10% water change every other day (basically a BGA clean out), but it keeps coming back.
For flow i have a 400 GPH canister filter and a 500 GPH powerhead. They are mainly aimed to circulate the surface (no splash, only small ripples). 2' tall, 8' long, 20" deep.
I am planning on a 50% water change/BGA clean out and a 3 day blackout. But for the long term improvement:
1) Given i am not injecting CO2, would it be appropriate to add some airstones (or actually an airline w/ small holes running along the substrate) to aerate the bottom; or would it be better to add another powerhead to circulate around the bottom (tank has angels, so they dont really love the current)?
2) increase KNO3?
3) 50% water change every 2 weeks?
4) Any creature to eat this stuff??
Thanks very much in advance!
Here's some pics: