Hydra in ACF tank

[Gemma]

I accidentally introduced some hydra to one of my ACF tanks. A few days ago I removed everything from the tank apart from the filter and some wood with plants attached and I did a 90% water change, but I'm still finding some clinging to the wood, the filter and to the (bare) bottom of the tank. I'm not sure if they're harmful to the frogs, but even if they're not I still want them gone asap because I don't want to spread them to my other tanks.

Does anyone know if there's a quick way I can kill the nasty little things without harming my ACFs, the bacteria in the filter or the plants I've got in there (java fern and anubias)?

[Mentat]

Hydra should not harm the adult frogs, although they are a danger to fish fry and small tadpoles.

To get rid of them the natural way, recommend boiling or baking the wood and cleaning filter. Either bake sintered glass (or porous rock) filter media or start with new one and use new filter pads, etc. Yes, that means will need to recycle the aquarium filter . Go over whole glass surfaces with clean pad or aquarium algae scraper and do a large water change. While you are doing this, soak the plants in a bucket that holds around 2 gallons of tank water and 1 tablespoon of aquarium salt for an hour or so.

Once you refill aquarium with dechlorinated tap; can add bacteria source (i.e. Seachem Stability) per label instructions to accelerate cycling. The next couple weeks you will feed the frogs a small amount of food on their normal schedule and vacuum the bottom daily (at least 10% water change). There has to be no food leftovers or any matter that can feed any surviving Hydra's in the tank. You will continue doing this until Hydra initially stop reproducing and eventually starve to death.

The chemical way is to add a Flukes killing chemical that will kill the Hydra. Flubendazole has been used in fish tanks with plants; but unsure if it can be used on frogs and at what dosage. If interested search the net for more information.

An option you could try safely, is to use a product called Hikari CyroPro. This is a pond anti-fluke treatment and it's safe for frogs at recommended strengths. Not sure if will kill Hydra's; but IMO it's worth trying. If you decide to use it, will have to convert the large treatment recommendations for ponds into the smaller volume of your tank. If need help with that let me know. Good luck !