I have a head-scratcher of a problem. I have kept tropical fish almost continuously for over 60 years. and consider myself reasonably experienced. I currently have 240, 125, 70 , 50 and 29 gallon tanks as well as a 1,000 gal aquaponic system. My problem is with the 240 which has been set up for over 10 years. Inhabitants are a large aro, large sev, 3 large silver dollars , a large flag tail prochilodus, and 2 medium geos. I have 2 large canisters and a 2-gal/hour continuous spring water drip with a wave maker for circulation. Ammonia and nitrites are zero, nitrates < 20. Temp 80 degrees, White filter sand substrate and lots of driftwood with biofilm. I feed daily aro pellets, bug bites and pleco wafers. All fish are healthy and several years old. The problem: any pleco I add dies within a few days. I have lost gibbiceps, common pleco, bristlenose and a feather fin squeaker. My recent heartbreaking experience was when moving a 7" Royal pleco from my 70, along with 2 geos. I drip acclimated them for an hour, even though parameters were apparently the same. The geos are doing well but, as with the others, the Royal died within 3 days for no obvious reason. No bullying., no gasping at the surface, etc. Could it be something in the substrate (which I stir occasionally), or the biofilm? The flag tail grazes some and the geos sift the sand with no ill effects. I'm considering replacing all substrate and decorations but I wonder if anyone has any other ideas? I've never had a problem like this. Help please!
Pleco Problems
- Thread starter Ozarker
- Start date
Only thing I can think of possibly the water is the issue. Test your GH and KH levels.
Did you buy the plecos from the same lfs? Also some plecos come from hard water areas.
I moved the Royal from another of my tanks with the same water , with a 1-hour drip acclimation. Same with the featherfin. a couple years ago. Those 2 I had for years before moving them. I added a gibbiceps from a lfs. All other fish in this tank are healthy and active and years old. It only seems to affect plecos and the featherfin. I use spring water which is hard and alkaline, pH 8.0. Same in all my tanks.
Hopefully a member will chime in with a solid answer.
I’m not too sure. I’d guess water issues and/or stress? Is there flow in the tank? Plecos from rivers with high amounts of dissolved o2?!
For an existing squeezer cat to be moved from one tank to another and die it has to be either significant water difference or real bullying. Those things are bulletproof. I would say same for gibbiceps although at small sizes they can be a bit hit and miss. But anything over 6” should again be almost bulletproof. I can’t see what could be in the tank or substrate to kill them, although old tank syndrome if it’s really been set up a long time with no significant changes, but way out there now.
Put a test pleco or catfish into a floating cage or inter-connected container into your problem tank. That will let you know if its a water quality issue (unlikely).
Yeah, that's what mystifies me - all those cats are tough customers. The 240 has been set up for around 10 years but I stir the sand when I clean and I moved the cats from a tank which has been running for 40 years. I wonder if it could be something in the biofilm on the wood, although the flag tail grazes with no problems.
That's a great idea! Thanks. I can place a small tank with a bristle nose to catch the overflow from my continuous drip system. Although I suspect it more likely has to do with the algae/biofilm growing on my wood. But then again, I have tried moving pieces of that wood to other tanks and the plecos slick it in no time. Go figure.
