algee

Question
I have a saltwater tank and I have this black color algee growing all over the sand and rocks. My tank is located near a window. Is the light the cause or do I have a bigger problem with tank..50gal. few fish..got a few snails to help, am I going in right direction????

Answer
Hi Francis,

From your description, what I believe you are experiencing is an overgrowth of brown/black algae, this is mainly caused from high levels of silicates in your aquarium water.

Below is some documented information, to give you some insight:

The silicates the Brown Algae requires to grow can enter your tank through several avenues, which could include: Commercial sea salts, tap water used for top offs, fish foods, and the substrate you may have on the bottom of your tank.

The source of the silicates must be identified and eliminated first, in order to get rid of the present brown algae blooms and prevent future outbreaks.

Check the source of any builders sand, play sand or other substrate materials in your tank which did not come from the ocean. There is a possibility that they may contain silicates which are leaching into your tank water.

Use only (RO) Reverse Osmosis Water or (DI) Deionized Water or RO/DI water whether you purchase an RO/DI unit or purchase RO/DI water from a commercial source.

Check to see if your commercial sea salts contain high levels of nitrates. If the salt mixture contains unacceptable nitrates, consider changing mixtures.

Removing the silicates alone from your tank will eliminate the Black/Brown Algae problem. But, as long as you are getting your tank in order, you might as well get used to dealing with nitrates. This would be a good time for you to establish a good tank maintenance routine which includes keeping nitrate levels at a minimum, especially if you plan to have invertebrates and/or a reef tank, which do not tolerate high levels.

(Recommended)

Make sure your aquarium is not getting to much direct sunlight from your window, for a prolonged period of time.

Create more water movement and circulation in your aquarium, especially in any dead-zones also known as a dead spot. A dead zone is a nook or cranny in your aquarium that doesn't receive much water current/flow.

Purchase and use Mangrove Plants in your tank or sump.

Check to see if your commercial sea salts contain high levels of ammonia/nitrogen.

Purchase and use a good "nitrate sponge".

Do not overfeed your tank.

Siphon the black/brown algae and uneaten food and other loose material (detritus) from the substrate.

Perform periodic water changes.

By reducing the nitrate and silicate levels, your tank will soon be healthy and free of the Black/Brown Algae. Many of your tank occupants (corals and other invertebrates) will also benefit from the reduced levels.

I wish you luck with all your future saltwater aquarium endeavors.

Best Regards,
Dave

All Experts - Editor

http://www.ocreef.com - Director