Backyard Aquaponics
A place to discuss aquaponics

we have about 100 fry together in two tanks. There are big size fry and small size fry. Big and medium size fry are pretty much are on the surface or in the middle swimming around. The tiny fry are all stay in the bottom and not really moving around. I don't think they are doing so well and small and small/medium size fry are keep dying one by one. I thought it was due to nitrate level and ammonia spike but even after I did water change and lowered the level, the weak ones seem to dye and some of small fry look like they have bulging eyes. I researched that fungus might cause bulging eyes in fish and once they are infected they lose appetite and show other symptoms. So I separated tiny fry and fed them, but they are eating so well.

Do you think the reason these small fry are dying is because they are not well fed or is it because of some other issues?

What is the best way to breed tilapia babies after they are hatched. I read in one forum that it is better to separate tilapia fry by size since they eat other fry that are smaller. It really stresses me to see fry dying one by one.

Do you have any suggestion?
Thank you so much!

Do some reading of the forum looking for adding salt to a system to mitigate against nitrite shock and for diseased fish; salting might help here?

Some were saying that salt treatment for small fry are not good for them?

If, after doing your due diligence by researching the problem and potential solutions, you are don't have a "final" answer then consider the problem like this: I've done nothing and the fish are dying; if I continue to do nothing there is a likelihood all of the fish will eventually die. Maybe the considered decision to do "something" is better than doing nothing, even if some people say the "something" MIGHT be harmful?

You don't have to jump to the total salt concentration in one hit, you could add a little and see how they fare, then wait a period before adding a little more?

Tilapia are a pest fish here so we're not allowed to have them, so I'm not really the person to ask, but there are plenty of others on the forum who have grown these fish, so hopefully one or more will soon pop up with some information for you.


Scott