Black algae?

Question

I have some algae growing in my freshwater tank that is black in color, is this normal? I have had freshwater tanks for years and never have seen black algae, my water is tested fine. Any info would be good thanks.

Answer 1

Is what you have "fuzzy" in appearance and grows on plants or driftwood (see photo: early stages: http://www.plantgeek.net/articles/gg_algae_faq/bba4.jpg late stages: http://www.plantgeek.net/articles/gg_algae_faq/bba1.jpg )?

If this is what you have, it's black beard algae, and it's a tough one to get rid of. Turning off the lights doesn't have as much effect as with green algaes. You can help reduce it by lowering the nutrients available in the tank (doing larger or more frequent water changes), but if you use tapwater for your aquarium water source, you might want to get a sample of your water tested, or get a copy of the test results from your water company. Some tap water may contain nitrate and/or phosphate, and these act as algae "fertilizers". So by doing water changes, you're only feeding the algae so it grows more. You may need to use reverse osmosis water (not distilled) which has these removed, or use a phosphate and/or nitrate absorbing pad in your filter. It also doesn't like water that's a higher pH. Usually it's not recommended that you change the pH of an established tank, so depending on what they pH of your water is, and how sensitive your fish are, you may not want to do this. If you do try to adjust it upward, use a small amount of coral or shells in a mesh bag in your filter.

You can try biological control, but snails and most algae eaters won't touch this stuff. Only Siamese (not Chinese) algae eater will remove it. These fish get around 5-6 inches, so only add one if you have room for a fish of this size.

If this is on driftwood, you could remove it from the tank and soak just it in higher pH water. If it's on plants, you can remove any infected leaves (it's impossible to get this off by scraping or rubbing the leaves - you'll only tear the leaves).

See this link for more info on its control: http://www.skepticalaquarist.com/docs/algae/tonealg.shtml

Answer 2

There are many species of algae with various colors such as green, red, brown, and black. The stuff growing on the glass inside your aquarium is probably mostly bacteria, but here are usually many types of algae growing among the bacteria. The combination of the bacteria and the algae may appear to be brown especially when viewed from the side.

At least once a month you should take a scrubber, that is labeled for use in aquariums, and scrub the glass inside your aquarium until the glass is squeaky clean. Click here to see a scrubber and read more about cleaning your aquarium.

The stuff growing on the glass usually does not cause problems but is unsightly, and most conscientious aquarists clean it off the glass at least once a month. The stuff growing on the glass feeds on the waste in your aquarium water.

You can minimize the rate at which this stuff grows on your class by removing 20% of the water from your aquarium and replacing it with fresh water at least twice a week.

You could also try a snail/algae eater.

Answer 3

If you do not have live plants it's not a big deal, you likely brought it in from where you bought fish, some big chain stores are very bad about having it. There are products that are safe for fish but not for plants that will get rid of most of what you see. My tanks are planted with live plants so I have to use another approach. Cover the tank totally so no light gets in at all for 3 days.(leave filters on) Tape black paper over the glass, cover it with heavy dark blankets etc so no light gets in. Algae needs very little light to grow but it does need some. This can knock it back some then do a big water change cleaning gravel, replace filters or media. Take any items like rocks, shells out and soak them 10 min in a 1 part bleach 9 parts water solution (unscented),you can go higher with the bleach % if your ornaments will take (natural wood will not but glazed ceramic ornaments will) Rinse everything and allow it to air dry before putting it back in the tank. Bleach is safe to use because it evaporates off completely and leaves no residue as long as you let it air dry. Also safe for aquariums is vinegar for hard water lines and white buildup. If this looks like little tufts it's often refered to as 'devils algae' its very difficult to get out of planted tanks.

There is only one fish known to eat this type of algae a siamese algae eater. http://www.thekrib.com/Fish/Algae-Eaters/ stores often sell chinese algae eaters mislabeled as siamese. The link above will help you learn to tell what to look for (make sure the stripe goes through the eye) because they are difficult to find and few store employees have any clue when it comes to this fish. They are a peaceful fish and good in a community tank, they are also pretty safe even in planted tanks where some fish are grazers.

Answer 4

look in the forum for answers to your black algea problem its hard to get rid of. its an imbalance of some sort it will kill you live plants. jhope it helps

Answer 5

black algea is not poisonus it just looks kinda rancid. but its easy to wash off.

Answer 6

yeah, i agree, black aglae isn't bad, but you will want to get it off. it will not harm your fish in any way.

Answer 7

ew. gross.