Aquaponic Gardening

A Community and Forum For Aquaponic Gardeners

Hi everyone,

i started my first aquaponic system about few weeks ago in Montreal, Canada. 

i started with 4 tilapias, all together about 3-4 pounds.

270 liter tank.

the tempeture inside the tank has been around 24 and a really hot day of 32.

two of the fish presented red soars and one was dead this morning and there is another one about to dye...


my ammonia levels have been high, so i have added a bacteria to accelerate the cycle of breaking ammonia.the fish looked a bit sick before i starting adding the beneficial bacteria.

also, two days ago i changed the water and i saw a drp down in tempeture of about 4-5 degrees, i thought this could have affected the two sick fish.


based on this, is there anything in particular i should do??


thanks for any support.

Views: 432

Reply to This

Replies to This Discussion

How were they tranported?  Were they open sores or did it look more like contusions?  We saw a similiar issue after transport of a large number.  Granted you only had four, but a lot of sloshing can easily cause bruising and compromise the fish's slime coat.  When the slime coat is affected, they are very susceptible to injury and will often expire quickly.  I liken it to us walking about without skin.  The dead and dying Tilapia will give off a huge amount of ammonia and too much ammonia, anything over 3ppm can inhibit the beneficial bacteria you just added.  I would suggest a partial water change, at least 50% for a reading over 3ppm and up to 75% if you are nearing 6ppm.  Your fish health is already precarious and the added ammonia will only add to their demise.   I would remove the one that looks like it is dying as well as he is only adding to the problem.  Do you have a fresh water, chlorine free source available?  Be sure of that before you add any.  Hang in there! 

In situations where you have more fish to protect, salting the system to between 1-3 ppt can help sooth fish as well as help protect them from nitrite toxicity.  When salting a system you want to use non-iodized salt since iodine can inhibit bacteria too and the anti caking agents in table salt are some times not good either.  I usually use the cheapest solar water softener salt or solar pool salt which usually runs between $4-$8 USD at the grocery or hardware store around here.  Dissolve it in water before dumping in the fish tank.  1 kg per 1000 liters will get you 1 ppt.


But as Gina says, do a water change to get your ammonia down and NO Feeding! Till the ammonia is down to a trace and then very minimal, sick fish usually won't eat anyway and uneaten feed is bad stuff in a system.


Do you have any pictures of the alive or deceased

what was the initial ph of the water where you got your tilapia

Because of the size of the fish I have to ask if you got these from a holding tank for sale to the public for food

Great point about not feeding TC!  I should have thought to include that but you always seem to catch what I miss in my comments.  Thanks for that!

Hi guys... 

i also got a problem with my computer, so i just finished reinstalling everything. 

so here we are: 

the other guy died, i am attaching few photos of the soars. they were transported in a star-foam box (photo). it might be possible what tilly said. 

i spent two months trying to get some tilapia or anything else edible around Montreal and i called all over Canada, including the ministry of acuaqualture and no signs of tilapia, so finally through a fish store i went to the place that supposedly received them from farms in the us, but anyway the way they managed the site..

so now. 

there are two alive, they seem ok. i have measure the ammonia and ph the last 3 days and its being 7.5 and 1.2 (ammonia) 

i am just changing the water, though, i am putting it, inside wine sterilized containers for few minutes so they loose up the chlorine. 


Two days ago, i putt nutrafin, 70 ml. aquarium=270 liters. 

and i repeated the dosis on the 24 of July. 


I am supposed to put 70ml tomorrow and in a week. Basically 3 more times. 


should i put the nutrafin? 

there is a driftwood inside, should i removed it? 


i am doing a water changed of about 30% and tomorrow a bit more... the tempeture went few grades down, so they might suffer. 


anything else guys on this?? what about the salt? should i still follow up on this?

Did you buy them live from a supermarket? If so they aren't handled so nicely and usually are on their way out.

just putting the tap water into a container for a few minutes won't get rid of the chlorine.  I would recommend bubbling the water at least overnight to get rid of chlorine if that is what your utility uses.  If your utility uses chloramine you would be better off getting a carbon filter of some sort (even a britta filter or pur filter on a faucet will work for removing chlorine or chloramine but you can get ones made to hook to a garden hose too.)

I fear constant water changes with chlorinated or otherwise treated water may well be keeping your system from properly cycling.

Some salt may help your remaining fish.  1 kg per 1000 gallons of water will give you 1 ppt of salt which will sooth tilapia and help protect them from nitrite spikes.  You want to use the cheapest solar water softener or pool salt, and dissolve it in some system water before dumping it into the tank.  Of course once you change water it will also mess with the salt levels so that all gets tricky to keep track of.

It is a bit tricky without the fish coming from a market.

I think i will refocus into getting fingerlings for early next year.

for now, i will see how the fish developed and in case they dont survive, i will continue with the system but just hydroponic.

there are about 2-3 warm months, so it might be no practical.

thanks for the help... 

if you cross by any info about fingerlings in Canada let me know.


You can run fishless (using some other ammonia source along with seaweed extract and perhaps something for phosphorus) but I don't really recommend going to hydroponic nutrients.

hey guys...

 i keep adding the nutrafin and it starting running... the ammonia went down and the ph is still at 7.5.

i wonder if it would be a good idea to add another tilapia ( less than a pound) to the system...


here is this info guys..

Conference to be held in Brisbane in 2012

Integrated Urban Aquaponics
Conference and Workshops
in Brisbane in July, 2012.

If your ammonia and nitrite have gone to 0 and do you have any fish left surviving?  If so, then you could probably get away with adding another fish.

Hi guys....


my system some how came along..... the only issue is the algae..... the container was a glass aquarium.

ph has been stable in 7.0 and ammonia 0.... all the plants are looking great....

ah the temperature is being 18.5 in the morning... i think the tilapia wont be happy for long time...


Reply to Discussion


© 2023   Created by Sylvia Bernstein.   Powered by

Badges  |  Report an Issue  |  Terms of Service