What Can I Do About This Algae Stuff

[LisaM]

My son has been keeping fish for 2 years and this summer we started getting this algae growing in the tank. It grows along the bottom really thick, not really attached to the rocks, we can reach in and scoop it up like picking up a blanket when it gets thick enough. It grows on the glass, not nearly as thick though. The water remains crystal clear and the fish aren't affected at all. We've tried malafix for two 10 day treatments with a water change inbetween and it didn't do anything except turn the algae a little stringy, but after a thorough tank scrub down to get rid of it all, it grew right back. We're at a loss at what to try next. Any ideas?

 

[minxfishy]

Has the tank been moved into direct sunlight? Also do you know the tank water stats?

 

[blue acara]

I think you have Blue Green Algae, BGA.
This isn't a true algae, but a bacteria called cyanobacteria that is able to photosynthesise. Covers everything in a blue/green slimy mat. Easily peels off but grows back again very quickly.
A blackout is the best method for this. Clean out as much of the algae as you can and do a 30 to 50% water change. If your nitrates are low then add some potassium nitrate to get levels to 20ppm. Turn off lights and cover the whole tank so no light can enter. Leave it for 3 to 4 days. No peeking and no feeding - fish will be fine without food for this period. After 3 to 4 days remove the covers and do a 30 - 50% water change. Make sure your substrate and filter doesn't become too clogged up with mulm and also make sure you have good water circulation around the whole tank.
Another option is to treat with Maracyn which is an anti-biotic. Seems to work well but may affect the biological filter.
If the BGA is originating from the substrate place some dark tape on the glass to hide the substrate from direct light.

http/www.theplantedtank.co.uk/algae.htm

 

[LisaM]

The tank isn't in direct sunlight, it's in the back of his room and he usually keeps his venetian blinds shut so very little light comes into the room to begin with. It's just a small 5 gallon tank. Do I know the water stats? No, we've never had a problem and the fish never die so we haven't felt the need to check the levels of anything. I'll try to the blackout. I'll take some water into the petstore and see if they can tell me anything about the nitrates. I've been trying to come up with how this problem originated, any ideas?

 

[PRW1988]

No clue as to how it originated, but try getting a moss ball or 2, or Java moss. Likely theres a build up of phosphates in the tank and the BGA is feeding off of them which is why it grows so much. Try the black out method, then mabye try some moss, it may help out, but even if not. It adds to the tanks design and it helps to lower phosphates and nitrates.

 

[aaronnorth]

You dont want to be lowering phoshates, and especially nitrates as this is the cause in the first place! BGa is a cynobacteria therefore lowering nutrients wont help anything, you can starve it and it will still survive.

causes include:

low Nitrate
ammonia spike
dirty filter (usually rotting causes an ammonia spike)

 

[PRW1988]

You dont want to be lowering phoshates, and especially nitrates as this is the cause in the first place! BGa is a cynobacteria therefore lowering nutrients wont help anything, you can starve it and it will still survive.

causes include:

low Nitrate
ammonia spike
dirty filter (usually rotting causes an ammonia spike)

ahh, well thanks for clearing that up for me. Learn something new everyday