Backyard Aquaponics
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in my trout farm are dying day after day at least 3 fish. if someone can tell me reason help plz ,
last week i found bloodsucker, leech( if you think it is there felt i will be gled to tell me how to solve this problem( here are photos of damages of my trouts)] if there are another idias plz tell me

Kind of tough to help without knowing anything about your setup. The first think I'll ask is what's the water temp. You should post your ammonia, nitrite, nitrate and pH readings as well. It would also be good to know about the number of fish and the size of the tank or pond, how much filtration you have and so on.

Looking at fish that have been dead for awhile won't help so take a look at the fish right after they die and look for signs of infection or parasites. Any signs that a predator got hold of them? Do an autopsy, and see if anything looks wrong internally. Observe how they behave before they die. Are they flashing like they are trying to scrape something off, are they swimming in circles....

It might cost more than the fish to have a lab take a look but someone with the state of Georgia might help you get in touch with one of their fisheries people.

Hope this helps.

PS - Unless you have a chiller or spring fed water I'm guessing it's water temp or low DO related to the temp being high. You may never know but there is a chance you can figure it out. Post your test results back and someone may spot something you missed.

Leeches can transmit a load of viral infections. 3 a day is how many of your stock (%)?
Post photos of your tank/pond, dead fish and if you can the leech itself.

i have farm on river, and maybe i have more then 800 fish. And i live in republic of georgia and here arn't labs to help me find out what is problem the fish before dying lays on surfies for 2 days and then just diyes because can't swim . can you give me a advice and thx vey much

You dont give any details, it could be anything.

Grab a camera and post photos and spend a few moments on describing your set up.
Ad on temperature and basic chemistry readings.
Happy to help but give me somewhere to start!

Republic of Georgia, whole different location than the State of Georgia in the US. It's still showing Tbilizi getting up around 33 C in the day - Water temps around 24 or 25 degrees C and above can be fatal to trout. At these temps the water may not hold enough oxygen for the trout. Check the water temp. If it's close to the limit reduce feeding and try to increase aeration. Do the other checks I suggested if you can. There's not much to go on as has been mentioned.

if you are farming in a river as you said, please also have a look at what is happening upstream, maybe somebody dumped something in the water, or spread some kind of chemicals in a field that then feed it to the river whilst raining.

As said above, to understand, you'll need to get some sort of water chemical readings such as pH, nitrites, nitrates...