Expert: Chris Robbins - 7/26/2006

Question
Hi Chris,
I am working in a pet store and cannot keep my
tanks clean from the black or green mold or fungus on the glass I clean them every two or three days, and have a large filter system that I change the  flilter charcole and just a filter pad, I have all kinds of fresh water fish, to the other side with goldfish and koi. I put stress coat in the water, and check the ph and its aroud 7.0 what else can I use to keep these
tanks clean and not have to use a pad on the glass every two or three days to keep it clean.

Answer
Hi Terri;

Sounds like algae. There are many types, even red and brown. Yours are probably brush, beard or hair algae. They can be very tough to get rid of. You probably need to replace water in the system more often. Algae is a type of plant and the more waste there is, the more fertilizer there is feeding the algae. Most fish store stock tanks are overcrowded and overfed. It's pretty normal actually. 25% of the water must be replaced at least once a week to keep them at even a minimum decent water quality. I cleaned mine twice a week. I usually did just a plain old regular water change once a week and did gravel vacuuming with another change later on in the week. I removed 25% twice a week that way.

I don't know how water changes are done with a central filtering system like yours though. Do you just drain it from a main line? I'm really curious about that! My tanks were all individuals with their own filters.

Anyway, here is a list of web sites about algae;

http://faq.thekrib.com/algae.html
http://www.fishpondinfo.com/plants/algaeinfo.htm
http://www.thetropicaltank.co.uk/algae.htm
http://mikes-machine.mine.nu/algae_gallery.htm

Good luck and I hope things are under control soon.

At Your Service;
Chris Robbins