Question about hydra.

[CitizenSneaky]

Hello everybody! I have a fairly new 10 gallon planted tank. It’s cycled, but at the moment only has a pleco, a nerite snail, and a tiny amino shrimp. Last week I saw two tiny hydras in the tank -- I scooped them out, and today saw two more, one of which was fairly large. Any suggestions on how to stop the hydras before they get too far? My ultimate goal is to get a betta, but I’ve been holding off on adding anything new because we’re moving in about a week.

[Guppysnail]

I don’t know how to link I apologize so here is a picture of the thread that ran yesterday that has a lot of information for you to check out. 

[mountaintoppufferkeeper]

I use fish to keep them down but also do not view them as a fry or fish health issue even when they blow up from live brine shrimp feedings for fry. If you reduce feeding microfoods they starve off and i would guess most fish eat them at that point. 

 

[HH Morant]

Dude! I never heard of hydra until I read this post. Then I read an internet article called "How to identify and Destroy Hydra (in just days)" Looks like the easiest way is to get a molly to eat them.

[Isaac M]

@CitizenSneaky first of all, nice aquarium! I like the big piece of driftwood! 

Here is an article on hydra and how to get rid of it by the aquarium co-op: https://www.aquariumcoop.com/blogs/aquarium/hydra

As mentioned in the article, it is possible that your future betta may consume the hydra. But also not overfeeding of smaller foods in general is typically a good way to reduce the population of hydra.

Either way, I have not seen hydra really negatively impact my aquariums when I have had it. 

[HH Morant]

I think hydra target fry and very small fish. Other fish eat the hydra. I have larger fish, so I have never seen a hydra.

[Daniel]

It reminds of snakebites and automobiles. People are often much more afraid of snakes than cars, even though 1 or 2 people die from snakebites each year in the US, but 30,000 - 40,000 die in automobile accidents. Poor water quality and/or a poor or inappropriate diet will kill your fry for sure, but almost certainly not hydra.

I often get hydra in my fry tanks when I feed (overfeed) baby brine shrimp. Although I am sure it has happened, over the last 50 years of raising baby fish, I have never seen a hydra eat a baby fish. Hydra love baby brine shrimp and baby brine shrimp are representative of the size of food hydra eat. The main drawback to hydra is that they can be unsightly if their populations are large.

I think pictures like this are what make people unnecessarily worry about hydra (but this isn't the way hydra feed in real life):

Take this video I shot earlier of hydra feeding, this is how hydra feed, and it is 99.99% tiny stuff:

 

 

[AlgaeIsYum]

It depends on what you're keeping. Fish are largely spared the effects of hydra as they mostly stay in open water. Animals that need to mostly move on surfaces like many inverts will suffer from a large hydra population. A hydra sting doesn't do any permanent harm to them but you can see it physically bothers them as they recoil from the touch. I assume it'd be like when we get static shocks, annoying when you get one but pretty stressful if you are constantly getting them. If you don't keep things like shrimp and snails and you only have fish you probably needn't worry.