White worms in tank

Question
Hello.  We have a 29 gallon freshwater tank.  Currently, we have one cichlid and one bottom feeder in the tank.  Over the past few months, we have lost five fish.  We weren't concerned when the first one died because it was about five years old, as was the second.  But the last three were only a year or so old.  

After the first four fish died, we cleaned the tank thoroughly and added stress coat and water treatment additive.  Then the last one died just today.  I got to really looking at the tank and discovered small white lines about a 1/4-1/2 inch long all over the glass and floating in the water.  I got to really looking and noticed the white lines were moving across the glass.

Could these little worms be some sort of fluke or parasite? We have never had a problem like this before.

Any help would be great.  Thanks!
Shannon Coe

Answer
Dear Shannon,
That sounds awful. The worms may have gotten in with the new fish, or new plants, or they could have blown into the tank, dropped in from the ceiling, or under your finger nails, or anything. It's hard to say.
I never had this problem, but I would suggest cleaning them out manually. If you can catch some in a plastic bag, take them to the aquarium store for identification. I don't recommend putting chemicals in the tank to kill parasites. Just keep cleaning them out until they go away.
Be careful whenever you have to do a total 100% water change. Usually this is very stressful for fish because they need to live in water that has healthy bacteria. Fresh water alone will not do a very good job of breaking down the uneaten food and waste.
If you have to do a 100% water change, add some biology. A good brand is "Cycle." It's a little pricey, but is the best thing to prevent fish loss. It adds friendly bacteria to the water. Add a little bit every time you change the tank.
Also, be really careful about temperature when you change the tank. That can really  make fish sick, especially in combination with other problems.
The next most important thing is to avoid over feeding. If any food hits the bottom, you are feeding them too much. This results in cloudy water, as well as creating a habitat for parasites.
At my site I have posted a basic set of habits for good aquarium health.  See:
http://steamboats.com/aquarium.html
If you enjoy the hobby, I encourage you to try again. We all lose fish once in a while.
Sincerely,
Nori