Backyard Aquaponics
A place to discuss aquaponics

Hi all, meant to join the forums and share a bit about my setup under more auspicious circumstances, but…

Long story short, my fish tank got too cold for too long and my tilapia (Blue) are not doing well. We've had quite cold weather here and the greenhouse is not keeping in the heat as I'd hoped (wished?). For a while just two of the largest were floating around mouth up/tail down, while the others huddled around the tank heater. I harvested one and the other seemed to recover once I started running a space heater 24/7 in the greenhouse.

A second 300W aquarium heater I ordered a few weeks ago at the first sign of trouble *finally* arrived yesterday and has brought the temperature up significantly — from 40–50ºF now to 50–60º. However, in the meantime four more have taken to just laying on the bottom. They fight some when I net them but don't move around much on their own. I harvested two more this evening but two are still laying in my tank.

My question is: do you think there's any chance they'll recover? I was hoping to keep them all alive until I could get a breeding tank set up inside, but now (besides the two comatose ones) there's only three young ones left that still seem reasonably happy. I was encouraged by the first one seeming to "snap out of it" the first week. Do you think another day or two at 60ºF might "wake them back up" as it were?

I had all of my Mozambique tilapia laying on the bottom of the tank on their sides. I brought them in, and lost most of them, but about 15 survived out of probably 35.

Lost 50 of my 80 golden tilapia to the cold in the past 3 weeks. I brought about 25 in just before a cold snap a week ago. If I had waited just a few more days I would have lost them all. The ones that I did bring in all recovered; took them about 4-5 days to start swimming around the tank.

Not Tilapia but on a related note -

Must just be the day. I walked out to bring in the Hummingbird feeder so it wouldn't freeze overnight. When I got it into the garage I realized a Hummingbird was still attached to the perch - it's been a rough week for them. Could be Torpor but I don't think this guys coming back R. I. P. little guy. I'll check on him tomorrow, just in case.

Thanks! The greenhouse will be under care of neighbors in a few days but I'll let the two live for at least a few more days and see if they can pull through. One of the ones I harvested was getting weird red patches on it, but the others look more/less healthy when they're in the net.

When I had tilapia they were not happy below 70 and died at 50, I've mentioned this several times and some people still try to grow them in the Winter without them being above 70. They are at least susceptible to disease when they are below their happy temps.

nate from what ive read expect a 50% mortality rate at 48 degrees I try to keep my tanks at are above 60 but I have the ability to cut my fish room off from the greenhouse every night and have a space heater in the fish room ambient temp around 80. I have had my water temps as low as 58 so far and no mortality so I expect they ones that survived will be just fine at 60 and on the plus side may just pass on that genetic trait for the next spawn.

My water got down to low 40's for quite a few nights and I never lost any tilapia, it wasn't till the water broke below 40 that they laid on their sides. My breeders in my house are not heated, and the house is kept about 62 inside for the entire winter. All my fish made it last year inside, and I believe they will make it this year.

Just because they don't cark it doesn't mean they are happy or growing. IMO It's pointless to grow tilapia in <70 degree water when other fish like trout would actually grow and not get sick. You should grow something that likes colder temps if you're keeping the water below 60.

True, but never seen trout for sale here. I put bass in during the winter, they are free for me. My pond is full of them. I was simply commenting that they will survive.

I think that my tilapia have a better chance of surviving in my tank than their original home. The Salton Sea gets COLD, and there is usually a major die-off in the winter. At least I give them a heater to hover around.