Tank going green

[chugga]

My new 40 gal tank which has been running for a couple of months now is going green. It appears to build up on the back wall and substrate, I keep cleaning the front and side walls, but if I didn't they would be green as well.

For filtration I am using a small hob filter, 2 powerheads, 1 pre-filtered and one isn't, around 30 lbs of liverock (And increasing) and a protein skimmer. I am using natural seawater, doing occasional top-offs with filtered tap water, probably around 1 gallon per week, but doing a 2-3 gal water change per week, using NSW. My lighting is 2 36 watt PC type fluros in a 30" reflector (White light), and an 18" powerglo fluro tube in a second light. This light is a tint of purple, and is a temporary arrangement until I can afford a good actintic set-up.

Would the green be because of lighting or water quality?

[Reefland]

chugga,

Is this just a little algae growing on the glass or is it filimantous algae like hair algae or Bryopsis? A little green film wouldn't be unusual and can be fixed with cleanings.

[chugga]

It's just a light film of green that gets darker every day. During the last week it has been growing faster, I have to clean it off every day now. There are only 2 chromis in the tank, and a bta, I don't overfeed them, but I do have the lights on all day...

[Reefland]

You should have the lights on all day, well between 10-12 hours.

What is you NO3 and PO4 readings?

[chugga]

Nitrate is between 10 and 20...Wow, that went up quick! I'll do a few water changes and see if I can get it down a bit, I'm guessing that could be the problem?

[BubbaWPB]

Nitrate is between 10 and 20...Wow, that went up quick! I'll do a few water changes and see if I can get it down a bit, I'm guessing that could be the problem?

Probably a part of it anyway....