Green slim

[hasq]

Set-up: 220gal+/-, HSA 1000 skimmer, 4cu bio-bale in DYI wet/dry, 25watt UV ster. rio 2100 for surface movement, little giant 5.5 for wet/dry, ice-cap with 7500k, F.O. tank with 150+/-lbs of live rock 20-20% water changes per mo (using RO-DI water) 2" sand substrate Readings Amonia 0 Nitrite 0 Nitrate 20-35ppm..... 2yr. established tank...Why do I have a reoccuring problem with green slim on the lower portion of my live rock, certain areas of my sand substrate, and my "dead" decorative fire coral?

 

[blutang]

Sounds like too much light time to me.
Later!

 

[nyyanks154]

Yup too much light, too much nutrients. Reduce light duration and make sure your skimmer is on when the algae starts to die!