slime on tank walls.

Question
I have had a 15 gal. fresh water tank for 10 years with a mix of tropical and goldfish, with only goldfish for the past 5 years. Currently we have 6 goldfish the largest 4 in. long.For the past 4 months we have been getting an almost clear slime on the glass. I do a 3/4 water change and wipe off the slime with paper towels. Within two weeks the slime is back, and I again wipe it clean, but no water change. Filter charcoal changed monthly,foam filter insert changed weekley. Testing done twice weekly and all water specs in line. We used to get a green or bronish alge on the glass, but since it is slimy that has'nt come back. Water temp. about 65 never higher.No heater used. Thanks, Ron

Answer
Hey Ron

I think your stocking is partly to blame.  The goldfish rule is 10 gallon per goldfish so this is where you could be going wrong. I would just keep maybe even one never mind six in a 15 but don't worry, many people make this mistake.  Get a 45 or 50 gallon for five of the fish and keep one in the 15 gallon or maybe kepp two if you really want to.  Keep the water changes, that is a good thing, many people don't even do those!

Now back to the slime, try adding a few cory cats to the tank.  They are bottom feeders and sometimes suckers!  Or add a few otos. These are lovely algae eaters and don't grow too big!

Good Luck and hope this helps!      Jack