green slimy algea and live rock problem

[haywood2]

Since my tank has been setup, about 4 months now probably, green slimey algae has constantly been growing on the live rock. At first my calcium was low, but now its up around 440. Ph I always have a hard time getting an accurate reading on, but its usually around 8.0 or higher. When I try to remove the green algea with my fingers, the rock seems like it's so soft it's just crumbling when I touch it. Anyone know what could be causing this? Nitrates are at 10, ammonia and nitrite are at 0. Thanks.

[itsthesong]

What are your phosphates reading? Do you use RO water? If not, this is a source of nutrients for algae. Do you have a fuge? A fuge would elminate the nutrients in conjucntion with RO water.

[haywood2]

The phosphates were reading about a month ago, but I added phos zorb to the filter so they should be reading 0 by now. I do not have a fuge and I don't really have room or money for one, so that's kind of out of the question.

[haywood2]

Anybody else have any ideas?

[Mark75]

Are you using RO/DI water? What are your TDS readings? Sounds like you have high nutrients and low flow in your tank.

[haywood2]

I was not using RO water but now I am when I do water changes. Shoprite has RO gallon waters for 39 cents. My flow rate is around 1100 gph including my filter, skimmer, and 2 powerheads. The tanks is 75 gallons. What are TDS readings? (sorry for my ignorance)