Nematodes in my tank

Question
Hi Nathan,

I have a 10 gallon freshwater tank. Bio filter, heater, some live plants,about an inch of gravel and 5 new cobra endlers - which I understand are a type of fancy guppy. We've had them for 2 weeks and I haven't done a gravel/water cleaning yet and apparently have been over feeding them because I noticed last night that I have worms in my tank! Ew, ew, ew!
I found a few articles online that say that planaria are not harmful to fish or humans, but when I read further descriptions, I'm pretty sure I have nematodes, not planaria, and I just want to make sure they're not harmful to me or the fish.
I'll start feeding less and cleaning more asap, but before I stick my hands in there I just want to make sure I'm not exposing myself to getting a tape worm or something. Gross...
Thanks for the research!
Lexy

Answer
Hi Lexy,

You can safely put your hands inside the tank rest assured that you won't get some kind of disease or infection. There are only two possible diseases that can be transmitted to humans, and they are salmonella and fish tuberculosis, and both are fortunately quite rare.

I can't tell for sure what kind of 'worm' you have in your tank, but I'm assuming that you looked at pictures, and concluded that it was nematodes. First of all, the term 'nematode' can refer to many things, from edible microworms (edible for fish) to parasitical nematodes that can kill your fish. Your type are harmless ones, and should not affect your fish.

It's almost impossible to manually remove them. The best option would be to feed very little for a week or two to starve the worms. They can only reproduce if they have lots of food.

It is essential that you do water changes, especially in the first months! During the first month, water quality is very bad because the beneficial bacteria that remove toxins have not yet naturally developed within your filter. Since you did not do any water changes, water quality became poor, which also led to the worms. During the first month, I recommend a 10% water change twice weekly.

After the first month, a 10-20% water change every week is ideal. A gravel vacuuming can be done once every two weeks along with the water change.

For your fish, you really only need to feed two small pinches. Fish should be fed a maximum of twice daily. Feed a couple pinches each time. Don't let any food be wasted, if your fish don't eat it, net it out. (If your fish don't eat it, you're reading way too much.)

Good Luck, and Happy Fishkeeping!