The Puffer Forum

Couldnt figure out what would be the best section to post this, but since I am asking about dosing medication I figured this would be it.

I have seem to come upon a hydra infestation in my somewhat newly setup figure8 tank. And they are multiplying pretty quick. I have read that formalin will kill them, I was wondering if this is safe to use with figure8 puffers and bumblebee gobies? Or any other suggestions are appreciated.

Anyone know what causes Hydra?

I had hydra a while ago in my tanks. I think I read that it is a sign of good water quality. They wont harm the fish. I just scrapped them off, did a few extra water changes and they eventually disapeared.

There are numerous different species of "hydra". Larger ones are capable of killing fish fry. My hydra were eaten by Procambarus sp., a crayfish (the parthenogenetic species banned in the USA). hydra in a friends tank died out after about three weeks without special treatment.

Does your hydra survive brackish water?

Well the tank is barely at .001 right now. Perhaps with some scraping and water changes along with upping the sg they will die off. They are spreading rapidly all over 1 piece of driftwood - but I dont see them anywere else. perhaps I could just remove the driftwood into a tub and treat it. I doubt that it was superb water quality that caused it... I have heard most of the time they hitch hike in live foods but the closest I have ever come to that is frozen, except for snails from my snail tank.

The hydra are translucent white, with trunks between 1/8 and 1/4" long with tentacles coming out the end. They appear to be budding all over, and there are several 'long chains' of them. I dont amagine they would cause my tank harm, but they kinda freak me out not sure if their stinging tentacles might be able to hurt the small bumblebees or not.

Well, the normal Hydra that I know of are a sign of good water quality, and mine cycled themselves out in a few weeks.

I would try increasing the salinity by a point, if your system is stable enough.

I was always told that Hydra is a sign of bad water quality, overfeeding, etc. Maybe I'm thinking of the wrong thing, little white worm type things that stick to the glass? Either way they are not a major problem and usually the fish will eat them or they go away as the tank stabilizes or the conditions get better.

I did a quick search on google images and pulled up this pic of a hydra that does pretty much look like mine.

http://www.hotzeltopf.de/albums/Polyp/S ... _Hydra.jpg

It doesnt appear that my Fig8's or BBs are interested in eating them. I may try increasing the salinity or just removing the afflicted driftwood and treating it seperate of the tank. Overall I guess my water quality is good, i just have some diatom and a few other types of algea I am trying to keep in check.

Leave 'em. THi sis a new tank. There will be many natural peaks and troughs in populations of a wide range of fauna. Don't start nuking them with chemicals - other organisms will jsut take their place.

In time, things will become more balanced. And they won't harm your F8s.