Floating White Wiggly Worms

Question
Hello - I have a 125 gal. freshwater aquarium with 2 adult Oscars (both 3 yrs. old) and a large albino catfish (added about 6 months ago).  I have been fight a bout of hole in the head. I finally got some good advice that seems to be helping, using live bearer salt and a Sera brand vitamin supplement.   This seems to be helping, in the last week the redness has disappeared and I believe the sores may be getting smaller.  About two weeks ago when I noticed thousands of these tiny white worms floating all in the tank, not sticking to the glass, but floating and wiggling wherever the current takes them.   They do not appear to anchor to the fish in any way, but I overreacted and did about a 90% water change.  I realize this was very dumb.  Initially, there were only very few of the worms, but now they are back with a vengeance and multiplying.   Also, on of the Oscars has started losing his "balance" and laying on the bottom of the tank at times.   What are these worms and what is the best way to rectify my ill-advised water change?   Also, any input on the hole-in-the-head treatment?

Answer
Hi Gareth,
The white worms are likely Planaria, which are very common in tanks with a high bioload such as Oscar tanks. They are harmless scavengers but huge populations mean the tank hasn't had enough frequent water changes and gravel vacuumings.

As for the hole-in-the-head this is always a tricky thing to try to treat. I've done it before. My best method has been to feed the fish the highest quality food you can afford, that means those that have high quality ingredients and vitamins. And pre-soaking the pellets in some human liquid vitamins until the pellets have become somewhat soft. The fish may or may not eat them but you have to keep working with them. I also treated the water is metronidazole medication for about 2 months. I'm not sure if this helped all that much or if the improvement on the diet and water conditions had the biggest impact on the dreaded hole-in-the-head. Sometimes it is recommended to improve on the overall care of the fish alone instead of treating with medications.

I know this is a lot of work but you owe it to your pet fish  to do your very best. Try to change at least 50% or more of the tank water every - to every other day. This will not only help treat your hole in the head, but it will get rid of your worm problem. Make sure to gravel vacuum well and make sure the filter is clean (rinse the media in tank water only) Do these water changes for as long as possible until the hole-in-the-head has healed. Thereafter, you can usually go back to about twice a week water changes, according to our nitrate levels and overall dirtiness of the tank.

Hole in the head is blamed on many things and nobody seems to really know for sure what causes it. But I do think that it is primarily caused by a combination of poor nutrition and poor water conditions. So improving these two things is most important first off. You may or may not medicate, its up to you. I don't feel its completely necessary....

These are the best articles I have found on HITH (hole-in-the-head) by far-

http://www.worldcichlids.com/diseases/Adamhith.html

I really hope this helps and Best of Luck!
Karen~