Bugs in our tank.

Question
We have a 55gal fish tank and we have two fish, a albino oscar and a sucker fish. We noticed that there are small green gnat like bugs on the glass covers. When we looked closer we noticed that there were small tadpole like bugs swimming in the water. We went to a pet store and they gave us some kind of water treatment and it didn't work. Any suggestions to what they might be and what we can do to treat this problem?

Answer
Good afternoon, Lacie.

I happened to be online when your question popped up, so let me write back right away in case you are still online also.

Bugs in the tank are not harmful themselves. What is worrisome is why they are there in the first place. Flatworms (planaria) only present themselves if the owner of the aquarium is overfeeding and/or is slacking on water changes and regular maintenance. The bugs themselves are harmless - just an unappealing eyesore and an indicator of less than desirable water quality.

The only bugs that will pose a problem are those that parasitize your fish, such as nematodes, and most can be seen using the naked eye. If you see bugs hosting on your fish, that is bad news. Until then, use these bugs as a "canary" a red flag that something is amiss...

1. Tell me about your water changes. While your tank is not crowded, both your fish are messy fish! Gravel vacuuming every week would be ideal, but at least once a month will be  a necessity. Water changes every week of 20% - or better yet, two 10% water changes a week - will also have to be performed to keep your water clean and your fish healthy.

2. Are you perhaps overfeeding? I noticed that when I had common plecos (I now only keep the dwarf variety) that I would drop in a couple of algae tabs every day, and it would not all get eaten the next morning. It seems my plecos preferred to graze rather than have two big tablets a night. So I cut back to one algae tab every other day, and veggies twice a week - romaine lettuce, zucchini, cucumber slices.

3. Make sure your oscar is not getting an diet loaded with meat (that is, protein) as this will pollute your tank and attract unwanted scavengers. Your oscar will love bloodworms and meaty pellets, but he will need some veggies too. Include spirulina flakes and spinach, your pleco might appreciate these foods as well! And please, do not EVER feed your oscar live goldfish. Feeder fish provide practically  zero nutrition and are a huge risk to the health of your tank. The grossly overcrowded, filthy rearing conditions that these fish are raised and housed in create an ideal breeding ground for disease and parasites. I don't recommend you feed beef heart (fresh or frozen) either, by the way.

I hope that helps, Lacie! A large water change (30% or more) and a thorough gravel vacuuming should help you get the bugs under control. Also, make sure all of your oscar's food is consumed within 2 minutes. The food that falls to the bottom will mostly pollute your tank - a little might be eaten by the plec, but not much. And always remember, if and when you test your water, 0 ppm of ammonia and nitrite and under 20 ppm of nitrate are the readings you want to strive for.

Thank you for writing in. Happy holidays!
Nicole

P.S. Here's an article about aquarium bugs and pests:
http://www.aquariumpros.com/faqpro/pests_1.shtml