ultra violet

Thought I was having an algea bloom....but have chaeto in sump. Nitrates are 2.0- 2.5 and phosphates are .08 - .04 consistently. Wondering it this is actually Diatoms, and if so, best way to exterminate. I have been running U.V. for 2 days. Very minimal change. Help!?

Hey Fellow Reefers, I just bought a new oversized UV Sterilizer (40 Watt - Able to handle 350 Gal Systems). I wanted to oversize it becuase I plan on doing a big upgrade later down the road. Current system specs are in the signature down below. I want to run it at 1800 gph. Question: - Does...