Backyard Aquaponics
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Hi, i have a 1000lT tilapia tank with around 80 mozabique orange tilapia (i think).

The fingerlings have been in the tank for about a week, yesterday two died.

Now im starting to see a large group of them just lying in the tank floor, not moving and not swiming (not sure if they are eating from the bottom or not).

The other half seem to be doing fine.

after i saw this i moved them for 20minutes into a 2-3% salt solution in case it was parasites or fungi.


This was yesterday and they still lay in the bottom not moving.


The tank is well aeriated, ammonia lvls are zero or very close to zero, nitrites are also very low, im not sure about nitrates (ran out of test kits for nitrates), PH is 7.5 and temperature is 25°c.


Any ideas about this? what could be the problem? it's almost half of the fingerlings with this behaviour so i woulnt like half of my fish to die.





Best regards

any advice? they are still not moving much, what could it be?

Looking at the TAN chart using your temp and PH, ammonia is toxic at about 1.5 but you say it is almost zero so should be ok there. Might be nitrite poisening as it can be a delayed effect, difficult to say.

Id say stop feeding, change out 1/4 of the water, increase air (if possible) and run CF (pull bells out).

why cf?

Plase help, my fears where well founded, they are starting to die.

An update photo:


What should i be doing, what do i look for in an "autopsy"?

How can i place them in intensive care?

You mentioned that you put them in a salt bath... By that do you mean you salted the whole system, or that you put them in a separate tank? If you salted the whole system, 2-3 ppt is great! If you set up a separate hospital tank, 2-3 ppt is not enough. Be aware that moving the fish to the hospital tank might cause enough stress to kill them too.

when you salt the hole system, what happens to the plants? can they handler 3% salt water?

it was a sepparate bath, how much shouldve i have put then?

Ok i just took a couple of living ones to check them closer, they have white little spots in the sides (more visible in the ones that are white temslefts, not the really orange ones), also some are flashing.

Ich? I've read heaps of threads on Ich and people recommend 5-6 ppt pool salt (NOT table salt), added all at once to shock the parasite. Warm water is better as it speeds the life cycle of the Ich.
If it was me I'd post a couple of close up shots of the fish with white spots and wait for a more experienced poster to confirm and advise, but have the salt ready.
I have dealt with Ich in aquariums before by raising the temp and salting, but still lost a couple of fish.
Good luck mate. Fingers crossed for you.

UPDATE: A photo of a sick fish, i think its definetly Ich

Im working on a fish hospital for my fingerlings.

Can anyone tell me:

1) Salt concentration necesary
2) Temperature recommended
3) lenght of the terapy
4) Other aditives needed to cure this?

Im planing on letting the fingerlings in the hospital tank (separated from plant systems) for a while, at the same time i will separate the fish tank from plants, empty it out and clean it very good.
The grow beds i plan on leaving in CF with water from the sump tanks.

Do you think this would work?

If it's Ich I'd be salting the system water or (I assume) the parasite will survive in the parts of the system that are not salted.

Salt your system to 6ppt and increase aeration if you can.

there wont be problems with the plants at 6ppm?

Most plants will be fine

Ok i made a little hospital tank for my Tilapia (100lt total), with a radial flow filter, aereator and a water heater.

temperature is 29°c
Salt 5ppm
PH 7.8
Ammonia 0
nitrate and nitrites unkown.

They have been there for for a day, but i still see the Ich.

Does anyone knows how long will it take to kill the parasites?