I have a 96 cf quad 6700 (about a year and four months old) and a 40 cf 10,000 and 40 cf actinic (a year old) over a 20 inch cube.

in the last couple of months I've seen a lot of bba and green spot.

before that I had well more snails for the spot algae, and a ton of pearling and no algae at all.. Still dosing EI, water changes weekly, and co2 is full.

can the algae be because the bulbs are old ... maybe changing the light frequency they send out? It was a friend's guess, but I hate to toss out good bulbs unless the guess makes sense.