How Do I Get Rid of Red Algae in My New Reef Tank?

[robertprice]

I set up my 29 gallon reef tank on June 13. It has 6 coral frags and a tiny Dusky Triggerfish who so far is reef safe and eats brine shrimp. It was spotless until we went through the recent cloudy spell: now I have a mat of red algae gorwing on about 1/4 of the gravel. There are also a few spots of green algae on the glass. The tank gets a few hours of direct sunlight in the early AM, and a 20 inch Reef Sun 50/50 tube and a 20 inch Home Depot plain daylight tube on it. It's right next to all my indoor plants in the kitchen window which grow really well.

The red algae seems to be emanating from one of the coral frags. The tank is filtered by a AquaClear 70 filled with a lot of Purigen and is otherwise very clean and clear.

[Qckwzrd]

your red algae may actually be cyano bacteria. I would test the nitrate, nitrite and ammonia levels of the tank. Also how often are you doing water changes? They do have bacterial medications you can use but this might have some negative effects on your beneficial bacteria so be careful. Tetracycline and Furan will kill it but you need to know why it's developing in your tank. Good luck.

[robertprice]

It was coming out of a single live rock, so I killed it with 1/2 strength coppersafe, then waited 3 weeks befoire I added anything. It looked like cyanobacteria, but I'm not sure if copper kills that.

[Qckwzrd]

copper won't kill it since its a bacteria. Becareful with the copper, it tends to stay in the tank for a long time.

[robertprice]

Actually, free copper can kill cyanobacteria (Copper Treatments For Dugouts), but I can't be sure it was cyanobacteria. It was very rose colored, and coming out of the one rock with a coral frag on it. The tank was also getting some direct sunlight so I added a background. Whatever it was, it raised my nitrates a lot. It's water under the bridge now, as the rock is gone and so is the stuff, and the fish are healthy.