Hydra Infestation

[OzieG]

Hi there I was wondering how bad and how hard  an infection of hydra can be to get rid of ... I have a 40g planted tank with about 35g of water, I have mystery snails, rabbit, and nerite snails, and I’m trying to grow out a about 30-40 ghost shrimp.. I’ve done some research saying use chemical in a tank but most will kill the snail and shrimp, I tried putting guppies in about 12 to see if it would help, I just don’t know anything about Hydra. Can someone help?

[ange]

I have a ton of hydra and currently no reason to get rid of them. My invert-only tank has green hydra and the population has risen following the rise of seed shrimp/daphnia populations. The hydra population crashed when those populations were seriously reduced. My 50 hex has white hydra and the population shot up because I overfed microworms and baby brine. The population has been gradually declining now that I've gone a few weeks without those foods. I also briefly had both types of hydra in my 10g but they're essentially gone, I believe that my sparkling gouramis and female betta found them tasty.

Personally I wouldn't worry. I've observed them eating microfauna but have never caught them eating fry (in the 50 hex) or Caridina shrimplets (in the invert tank).

[Maggie]

I have hydra too! I don't like it at all, but the chemical alternative is drastic, and they aren't as dangerous as the web seems to indicate. My rasboras have kept it in check in the top half of the tank (they don't really utilize the lower half  much, except when playing "sprint races" with the Otocats at night, and during water changes). My next fish will be pearl gouramis and hopefully they will also find them tasty. Because of the way hydra reproduces (a single cell soon becomes an entire organism and can reproduce asexually), I feel like its almost impossible not to have it in an aquarium, especially if you have live plants and/or feed live food.

[Colu]

Blue gourami's Molly and paradise fish eat hydra

8 minutes ago, Maggie said:

 

 

[Daniel]

I think I have hydra in both my fry aquariums and in my aquariums with ghost shrimp. I definitely wouldn't use anything chemical to get rid of them. Personally, I think they are cool interesting members of the ecosystem, but others don't share that view.

I don't have any hydra in aquariums with adult fish in the tank. I have seen sparkling gouramis, guppies, swordtails, all munch down on a hydra, and if your aquarium has any livebearers or gouramis you will probably have zero hydra.

Their population drops drastically also when there is no free swimming food for them to eat. The reason my fry aquariums have hydra is because I feed those aquariums baby brine shrimp and baby Daphnia. Once the food source is cut off, the hydra disappear.

Here is a hydra in one of my baby sparkling gourami green water aquariums catching baby brine shrimp.

 

[OzieG]

Thanks for all the help, I did put some guppy’s in to see if they would help, have you had any big problems with fry populations in you tank with the hydra?

[Jack.of.all.aquariums]

I was able to eliminate hydra using SL Aqua Z1. It also killed the planaria as advertised. I did so after watching hydra eat a baby pufferfish. My many "pest" snails did not like it but it also didn't kill them and the cherry shrimp didn't seem to mind. The product specifically lists being dangerous for nitrite snails. I suspect that you would want to house all of your snails in a different tank if you were going to use it. 

All that being said I don't believe that there is a reason to kill them if that tank isn't being used to raise baby fish or shrimp. 

Edited December 18, 2020 by Jack.of.all.aquariums