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Aquarium Advice Newbie
Apr 26, 2005
I am having a horrible time with brown algae. I have a 100 gal reef tank, with a few clowns. I can not get control over the algae.

What causes brown algae to grow.

What products remove brown algae

What do the products actually do to remove the algae.

Do different types of fish, to many fish, no fish at all affect the growth of algae

Please help!

Welcome to AA!

Here are some things we need to help answer your questions with:
1. Water source - tap, RO, RO/DI, Well, etc.
2. How long has the tank been setup for.
3. Lighting type and is it near a window.
4. Feeding schedule - how often, and how much.

If you can answer these, we can try to assist you with this problem.

What causes this brown algea is excess bioload. You may be overfeeding your livestock. Another thing to keep in mind is the amount of time you leave your lights on. In the ocean the fish only experience about three hours of direct sun light a day durring the high noon. Algae is photosynthetic so anything past seven hours even with moon lights is only going to contribute to the problem. I would not advise any chemicals, use these only as a last resort. Stop hair algae is one product should you decide on treatment. Manually pull out what you can. Cut back on feedings and increase water changes (twenty percent twice a week). Using DI water is the best thing you could possibly use to fight this problem. Using tap or UV or even RO will leave trace elements such as amonia and phosphate that will only add to the problem. Wet dry are not what they are cracked up to be either. Using a protein skimmer will help remove any left over food or fecal mater. The Foxface should be trimming the algea, but may not be able to catch up. I don't know what you are feeding them but flakes are a big no no too. I deal with this all day. If you have anymore questions please email me. Good luck!
I feed flakes on occasion, but mostly frozen foods. 20% water changes twice a week? I haven't heard that one before.
RO is still better than tap in most cases, however, the RO system I have doesn't leave traces of ammonia and actually assists in pH buffering.
My lighting is on 10 - 12 hours a day and that doesn't cause any problems with algae.
Let's see what Robstills has and we can trim the fat from there.

Is the algae slimey or simpley a dust like coating? For the most part the foods you feed will contrinute to green algaes as they are a source of organic phosphate. they are not typically an issue with brown algaes. The main causes of "dust like" brown algaes is silicates in the source water unless the tank is still recently new. New tanks will commonly have this problem and should abate on it's own unless silicates continue to be introduced. If your source water has silicates, the RO unit will not be able to remove them. Only a DI resin will be able to remove silicates, same goes for PO4.

If the algae is slimey like "snot", it's a dinoflagellate bloom which can be quite hard to get rid of. Manual removal and constantly keeping the pH in the higher 8.4-8.5 range 24/7 is about the only way to beat it.

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