Brown/black algae

mizzouHHR

I'm having a bit of a brown algae outbreak and I'm not sure what is causing it. I have a 29 gallon aquarium that has been running for well over 3 years. I've not had any fish die, or give any signs of stress. Of course I do 40 to 50% water changes every week. I'm very careful about over feeding and I don't believe my tank is overstocked. I have 4 tiger barbs, 3 gold barbs, 2 odessa barbs and one gold gourami. All fish have been in here for several months (some for up to 3 years) and get along great. From the research I've done, it list the causes of brown algae to the light spectrum changing over time, and to silica. I've replaced my bulb with a full spectrum light and that didn't change the problem. I'm not sure what to do about silica, or if that is the problem. After I clean the aquarium it takes a couple of days, but sure enough the brown algae starts appearing on the glass and especially on decorations. I have not used any chemicals as I'm not sure that would be healthy for my fish. Currently I'm at work so I can't post the exact numbers from water tests, but I can tell you they are all within the "safe" limits. I can post more precise numbers when I get home this afternoon if needed. Any advise would be great appreciated. Thank you.

syrinx

Is this a brown "film" on glass and ornaments, or the furry looking "beard" algae?

syrinx

- I just re-read the thread title, and I am going to assume it is beard algae, since the othe kind doesn't look black. This stuff is near impossible to completely eradicate without removing the fish from the tank. In my tanks more frequent water changes seem to slow it down, but you are already doing pretty aggressive pwc's. I have heard Siamese Algae Eaters will eat it, but I have never tried it. If you can encourage green algae to grow, it may "crowd it out", but then you'll have green algae. You can soak decorations, filter tubes etc in a bleach solution to kill it , but it will eventually come back.

If you are looking for more information on it, look for Red Algae, as that is actually what this is, or brush algae it is sometimes called. And If you find an easy way to get rid of it please let me know, seems like it always appears in my tanks after a few years.

The only good news I have is that in a "naturally" decorated tank with wood and rocks it doesnt look too bad as long as it is kept under control. It kinda makes things look more natural- river and lake beds are seldom sterile looking. But it doesnt go well with plastic castles and the like.

mizzouHHR

Thanks for the reply. The decorations in my tank are two large pirate ship halves, so the brown/black algae don't look out of place, but it looks much better clean. To describe it on the glass, it kind of looks like it's been airbrushed. It comes off the glass very easily with a magnet cleaner. It's a bit tougher to get off the pirate ships, but comes clean with a toothbrush and warm water.

syrinx

Hmm, this sounds like the other type. I guess I have never seen it thick enough to look black. If it comes off easily it is definitely not beard algae. What you have is actually diatoms, not technically algae, but often referred to as brown algae. I dont have as much experience with it, it often appears in new tanks then goes away on its own after a while, usually after green algae starts growing. I cant be of much help how to get rid of it.