water/algea question

[stumpy]

I have a 30 gal tank.I do 2 gal water change every saturday morning. I always test my water the night before and it has been perfect. The tank is 5 months old. I went thru the brown algea stage already. A few weeks ago I started buying reverse osmosis water from a machine at my local Kroger grocery store (before I always used distilled water). Since I started using the ro water I have real bad green algea. It covers the sand bed like a carpet and is starting to come up the glass. I try to scrape it off the sand bed but it just balls up the sand. Any suggestions? This stuff makes my tank look real ugly!

 

[jackdp]

Be sure your RO water isn't high in nitrates or phosphates. What type of filter do you use? If you are running carbon and haven't changed in awhile it could be letting nitrates back into the tank. Is your tank water testing high for phosphates or nitrates? Is there any livestock in the tank? Be sure you're not overfeeding. You could just be going through another stage of tank development, I remember my tank going through brown algae, red algae, green algae and now its in a bubble algae phase.

 

[stumpy]

My test kit does not have a posphate test in it. I use a bio-wheel 170. Its been a month since I changes my filter pad but I wash it out every water change. My nitrates are always 0. My live stock is 1 firefish,1 clown,1 cleaner shrimp,2 snails,2 crabs,3 urchins. I don't think I overfeed. I feed once per day and it usally always gets eaten. (the shrimp and crabs go crazy with what makes it to the bottom)

 

[scuba_steve]

i would check out the ro at the store heck and see how often they change the filters i'd bet not often enough