Algae & Lighting

[cathyjane]

I finally got my new lighting system up and now I'm seeing a lot of the red algae associated with too much light. Is there anyway to control this?
I have a CustomSeaLife 48", 2 10,000k & 2 Ultra-actinic with the moon lights. I have the main lights on less than 10 hours per day.

[loganj]

How much flow do you have in the tank? What are your water parameters?
pH, alk, cal, nitrate, phosphate?
Alk and calcium doesn't really have a lot to do with the cyano (that's what it sounds like you may have), but it does promote the growth of coraline. The more coraline you have, typically the less of the "problem" algaes you'll see.
Nitrate and phosphate are used as food by the algae. Cyano often will not do well in direct current either.
You might try running just the actinics for a few days. I've never tried this, but I remember reading a post by another member whom I believe had success with this method. Might be best to verify this before you do it though. HTH.

[cathyjane]

My Ph is 8.2 and my nitrate was 40ppm before I did a 20% water change a couple of days ago. I don't have any tests for the alk or phosphate. I do change water out with RO\DI water. I didn't really have this problem until I got the lights. Thanks for your help I'll try to find tests for the other two items.

[loganj]

The light was the missing link that the algae needed. 40 is kinda high for nitrates and that is likely a big contributor to the problem. It's not uncommon to have an algae bloom after a lighting upgrade. Siphon as much of the algae out as you can when you do a water change and try to get those nitrates down below 10...0 is the target.