I've searched on the internet, and have found mixed reviews about tilapia raised in ponds with chara and their table fair. It's also totally up in the air as to how much chara these fish will even eat, but regardless they are still in the water with the noxious weed. I'm feeding pellets, but as most of you know, optimal bluegill food is not cheap. I've read about purging before cleaning, and was wondering if a few days in my aquaponics system would suffice to get any "bad taste" flushed out of the tilapia.

Interesting observation. Have you tasted tilapia from a pond that had chara? Chara is common enough that it seems this issue would have come up already.

How do you propose to harvest your tilapia before they make it to the table? I'm not sure that is an easy undertaking.

Firstly are your tilapia fillets having "bad taste". I question if Chara causes off flavor of tilapia fillets. Off flavor could be caused by another factor. A research study was done on tilapia, I think blue tilapia, feeding habits using four plants. They found that Chara was the most preferred food, even more consumed than filamentous algae. I don't think the genus of filamentous algae was determined. There are many genera of FA belonging to Chlorophyta - greens, Cyanobacteria - bluegreens, and Chrysophyta- golden browns, plus a few red and brown FA algae.

I haven't harvested any fish yet, largely because I haven't been able to catch them on rod and reel or by cast net yet. That is encouraging though to know that Chara is not likely the cause of any unpleasant flavors, because otherwise the water quality seems great.

Chara causing an off flavor is probably urban legend and "assumed" since common farmed fish, like catfish flavor is affected by foods eaten.

If an off flavor is found in tilapia fillets, it is likely from intestinal fluid contamination.

Purging only clears the intestinal tract, again, the main source of contamination causing any off flavor. And if your aquaponics has tap water clear water, it will be good for purging.

Connor I ask about harvesting tilapia only because many/most of us in cool weather areas would like to harvest and eat our tilapia before the coons get them in the late fall, but no one seems to know how to do it effectively. I have not found hook and line to work. Some type of net, trap? Not sure. I keep hoping someone smarter than me will figure out a good way to harvest them in the fall.

I have eaten wild/natural foraging tilapia many times and they all taste like mud to me. I tasted one that a guy had in his smallish concrete koi pond that flowing artesian water for a few weeks. it ate some koi pellets during this time. It tasted much less muddy.

Geosmin is one 'bad' flavor in the water produced from algae usually Cyabnobacteria (bluegreens) and some bacteria. Geosmin type chemicals are what usually flavor fish fillets and water. Web search geosmin.
http://www.microbac.com/uploads/Technical%20Articles/pdf/Geosmin%20and%20MIB%201.pdf
FromWiki: The human nose is extremely sensitive to geosmin and is able to detect it at concentrations as low as 5 parts per trillion.
Geosmin is responsible for the muddy smell in many commercially important freshwater fish such as carp and catfish. Geosmin combines with 2-methylisoborneol, which concentrates in the fatty skin and dark muscle tissues. Geosmin breaks down in acid conditions; hence, vinegar and other acidic ingredients are used in fish recipes to help reduce the muddy flavor.[9]

I have good luck catching tilapia with hook and line by firstly regularly feeding the tipalia pellets. Secongly you should fish for tilapia before the water turns cool and definitely above 65F when tilapia are still active. When you want to catch the tilapia use an artificial pellet such as Stubby Steve's or Berkley Power Bait as bait on a small hook under a small bobber near or at the time when you are usually feeding pellets. Use a small light wire hook such as Aberdeen #6.

Thank you for the feedback men, that puts some worry to rest. All the tilapia I see are visibly fat, but none are over 3 or four inches long. I tested visibility today with a foot long white frisbee, and measured 54 inches just after direct sunlight stopped hitting the water (around 8:15 right now). I'm assuming the larger fish typically hang out deeper? Also, broodstock tilapia were added June 2nd if that helps with estimating how large the 2nd generation fish should be.

The Tp in my pond last year had a good clean taste, I was surprised!!. But they lived on fish food from the TH feeders, after introduction to the pond they did a good job eating the FA and so later I had very little FA for them to eat. I hope they will taste the same this year.

Tracy

I put 50 # of TP in and that was the last I have see of them. No babies and no adults.... A black hole. Maybe the eating the blue green algae.they don't surface at the feeder that I can see. Last year saw no dead ones when it got cold

Pat, last yr I had Tp at every feeder, they were added to the pond before I added the lmb. But this yr I add them and like you I have not seen any Tp at the feeders or at last years spawning beds. There is a lot of FA growing in and around the pond this year so I am pretty sure they are there eating away. Or I hope they are

Tracy

Pat, I very rarely see any dead Tilapia in my pond. When I say rarely, I mean one or two per year after they die in the fall. 99.9% seem to be consumed by something as soon as they slow down or die.