Do My Fish Have Flukes?

[Guest Fishy]

When I cleaned my tank yesterday (20% water change, as usual), I saw some white wriggling creatures in the water - dozens and dozens of them I have not seen anything like it before. They were all only a few mm long with very narrow bodies and no discernable heads.

I have four very healthy-looking fantails in the tank who are not acting in the least bit ill. They are not flashing, scratching, gulping, clamping their fins or anything like that. I have had them for the past 2 1/2 years. The only thing I've changed in the tank was a new plant (introduced about 2 months ago). I did not see the worms when I cleaned out the tank 2-3 weeks ago. Also, the fish have not had any live foods (unless you count the food in gel?).

Should I be worried? I cannot see any of the 'worms' attached to the fish at all. The fish are all eating and pooing well! Can anyone hazard a guess about what the worms really are?

[sandy]

these will be planaria and are found in nearly all aquariums (and are harmless) but the amount depends on the amount of cleaning that is done. when changing water use a gravel vac and cut back a bit on feeding.

how often do you do water changes and how? and how often do you feed your fish?

[Guest Fishy]

Thanks for your reply. I was worried that they might be dangerous. I tend to clean the tank every two weeks which includes a 'window clean', a gravel vac and a 20% water change. I feed the fish once a day. The tank is crowded, which I am not happy about but I am not able to upgragde at the mo.

Would you recommend that I do a really thorough clean out with removing gravel etc. or should I just clean out more regularly? I will cut back on the amount that I do feed.

Do you think the planaria were introduced with a plant? or have they always been there in small quantities?