Algea.

Question
Hi, I had a 38Gal, marine tank setup for almost a year. I aquired some new LR at a yard sale I soaked it and skimmed it for about 3 months, now I upgraded my tank to a 60Gal. All the new LR is now growing Brownish algea. I believe it to be Cyano (or something) how do I get this out and make it nice again? The tank contains 1 Blue damsel, 3 four stripe damsel, 1 six line wrasse, 1 sally lightfoot crab, and a few small hermit crabs. I have placed a carbon filter in the tank, but that has had no effect. all my readings are 0 or very close to it. What can I do? I can send you pics if that helps. I think I need a different way of contacting you. I am unable to send pics through here.
thanks


Answer
Hi Chris. cyanobacteria is not typically brown(it can be but it is not common) but can be green or red to a very dark maroon. Cyanobacteria is very slimy and will come off in almost tissue paper like sheets. If your tank is newly set up what you are most likely experiencing is a diatom bloom. This form of algae often blooms in newly set up tanks and can last anywhere from a few days to a few weeks. Diatoms will have a rusty, powdery appearance and can be easily blown off the sand or rocks with the use of a turkey baster or power head. Diatoms are more like a dusting where cyanobacteria is more like a thicker sheet and can not be blown off quite as easily. The best thing to do for a diatom bloom is to simply let it run its course. A cyanobacteria bloom usually happens in a tank that has been set up for a few months and is an indication of a high dissolved organic waste in the water and can also indicate improper filtration and not enough water movement in hard to get rid of cases. Some people think it is a normal algae bloom to go through but I have found that this is simply not true. A well maintained tank with a very good filtration system should not ever see a cyano bloom. The best way to get rid of this "algae" is to figure out why it is forming in the first place. Overfeeding, stagnant areas in the tank, too many fish added too fast, overstocking, insufficient protein skimming, too many nutritional or trace element additives, infrequent partial water changes, doing water changes using tap water, low quality sea salt mix, low alkalinity, and not enough filtration can all be factors to consider when figuring out how to get rid of a cyanobacteria problem. Never use medications said to treat slime algae. These medications are antibiotics. While they won't harm your biological filtration, (one is gram negative and the other is gram positive) the cyanobacteria can build up a resistance to the use of this antibiotic and when it comes back(and it will if conditions are not improved that caused the outbreak in the first place) it will be a more resistant strain and also will be even harder to treat. If you would like to send me pictures you can feel free to e-mail me at   tankgirl527@hotmail.com
I will be at work for 13 hours on monday so it may take some time to get back to you but I will check my mail as soon as I get home from work and will help you out then.