Backyard Aquaponics
A place to discuss aquaponics

Since last post we have had a cold snap with night temps down to 40degF (5degC) and the water dropped to 66degF (19degC). Then we added 500watts of heating and temps moderated and the water is back to 70degF (21degC) as of 12 hours ago. Chris pulled two more dead tilapia out (bummer, but deaths are slowing, although possibly not as a percentage of remaining tilapia), got startled by a large pleco he did had not previously met, and tried not to upset the three catfish bumping his legs as he swam in the darkness. *grin*

I'm looking at a balancing act between warming the fish enough for their immune systems to work well and keeping it cool enough to retard the disease.

Well, I'm back.

So, climbed into the FT today and found 1 dead tilapia and the remains of the carcass of a pleco. Surprised to find only 3 tilapia remaining, so I may take them indoors to the 50 gallon tank with the two babies already there.

Remaining fish in the big system: 3 each tilapia, goldfish, and catfish.

So, now what? Not really a good time to introduce koi, esp with possible disease. Same for goldfish. I have some ideas on ways to source cats, but that is a bit iffy and don't want little fingerlings with the big guys. Tilapia are out for now as winter is coming and it will be nice not to heat the system. I wonder if I could source some trout from a friend of a friend who works in a hatchery, but I would not want to add them to this system until all deaths cease for a month or two. Hmmm, things to ponder...

I think I need a vacation!

My final post on this thread:

I was wrong about the lone pleco dying. There was a second one who has been moved today to the slightly warmer indoor/outdoor system. It sure has grown in the year in the green-shed (definitely not a green-house) system.

While swimming in there in 11degC (52degF) water I also captured the final three tilapia. These weighted a total of 1190grams (a bit under 1 lb each). Disappointing for two years old, but most of that was well under optimal temperatures. Final analysis: some abdominal fat deposits, good flavor, disappointing meat yield. Apparently these were a breed more decorative than meat, supposedly a pure Mosambicus. Two went as an appetizer before pizza, the final one will accompany my breakfast.

So, no more deaths after I came home. The trout I've added (in a separate tank circulating the same water) are doing fine. I don't think I can come up with any more likely scenario than I did before: a lone fish dying, unnoticed, polluting the water, causing cool-stressed tilapia to die in domino fashion.

So, after two years of raising fish, I have harvested a grand total of four at great expense. Disappointing, but I've also gotten a lot of great veggies, learned a lot, and had a lot of fun, so the balance is not great, but ok. I'm finally doing gardening not just as a way to grow food, but as an experiment and THAT is FUN!