Hydra in my QT Tank

I have had my 10 Gallon QT tank setup for quite some time now. Probably a good 2 months. I have used it for 3 different groups of fish. This is the first time I have ever noticed anything slightly bad with it. I noticed hydra in the tank. After looking for about 10 minutes I have spotted maybe a dozen. I currently have 2 Furcata Rainbows and 1 peacock Gudgeon in the tank. I think they are big enough to be ok but I don't want them stung how do you get rid of the hydra.

I have a heater on the tank, HOB filter but no light. So I know the light isn't the issue. Because I heard to much light and food can cause them. How do I treat it? I have coppersafe, freshwater aquarium salt, ich clear, and fungus meds from previous fish problems. Do I need to treat with meds or should I just syphon out the leftover food every night?

Also what could have caused this? It just broke out after I got the fish a week ago. Could they have hitched on the fish even though I netted them and dumped the bag water? I did start feeding frozen blood worms around the same time though. And I did see 1 lone hydra in my main tank but dissapeared. Maybe my dwarf gourami ate it since someone said gourami sometimes eat them.

You can see them with the naked eye. They look like clear to white anenome. Pretty small, like barely visable by the naked eye. They can easily be seen on the glass if you look closely. do a google for freshwater hydra.

Back to my problem. I also heard that rasing the water temp to 100+ for five minutes will do it. I was thinking about netting the 3 fish putting them in my bucket and doing a 50% water change with as much hot water as possible. So the temp raises above 100. I figure remove the filter to make sure you don't kill any bacteria but keep the rocks and pvc that the hydra are on and the shelters for the fish. It is a QT tank so it's not like there is gravel or live plants or anything. Just fake plants and rocks and such.

I just think this is safer then using meds, if the fish aren't sick why dose them with meds. And if I ever get new inverts to qt I won't ever be able to use this tank for them, and I won't ever be able to convert this to a invert tank and 10 gallons is a perfect shrimp tank size.