Bad pH for C. Trilineatus?

[Bignose]

About 6 weeks ago, I purchased 6 Cory Trilineatus, and after a short acclimation period (LFS uses same city water as me) introduced them to the menagerie community tank. After a few days of swimming up and down and everywhere as new Corys are wont to do, they settled down nicely, and I thought they made a nice contrast to the 6 C. Aeneus I have had since August. The Aeneus seem to be thriving (the lemon tetras enjoy it when they spawn since the eggs seem to be quite a treat) but I have lost 4 of the 6 Trilineatus in this short time. At least two of the bodies I have had to remove showed noticable redness around the gill area -- what could this be indicative of?

My local water is hard and alkaline, the tank pH always between 8.2 and 8.4, I am just wondering if this was too much for the Trilineatus? Are Trilineatus normally wild caught or tank bred?

Thanks in advance for any help.

 

[tekknocolor]

http/www.planetcatfish.com/catelog/calli...ydora/508_f.php

 

[Apache]

Sorry to hear about your loss. The first cory I ever owned was a Trilineatus, and she was great, but she died after about 2 months. We, too, are unsure what caused her death, but we think it was high nitrates.... The only visible sign I noticed was that she seemed more sluggish in her last days, and she also had the redness around the gills, but that was it... Can't help much more than that.... Sorry. Hope you find an answer.

 

[Bignose]

I have seen that planet catfish site, and while I respect them over most other internet sources, I have seen on the net and in books that trilineatus' range can go up to 7.8 ish, so I thought after acclimating them 8.4 is not too bad. They are often described as 'hardy.' I also don't think it was nitrates, since I do a weekly 25% water change and java moss sucks up a great deal. My water tests never read above 20 ppm, and usually about 10 ppm.

The good news is that I has assumed 4 had died since I never ever saw more than 2... and today I saw the third one! So, maybe not quite as bad as I thought, though I am still not too happy.

Anyone know if they are typically wild-caught or tank-bred?

 

[Inchworm]

Hi Bignose

I suggest that you ask your lfs about the origin of your particular corys. If they don't know if they are wild caught or tank raised, they can find out from their distributor. I don't know for sure, but I suspect that at least some of this kind are tank raised. If they were quite small when you bought them, it's not likely that they were wild caught. You might also ask your lfs if any of their other customers reported problems with that batch.

As far as your nitrites go, you might want to do larger, or more frequent, water changes to eliminate them completely. Perhaps you might also consider adding more filter media (if that's possible with your filter) to cultivate more beneficial bacteria, which will help with this. Twenty five percent a week is not a very large water change, especially if your tank is well stocked.

Three lined corys are not usually considered delicate or difficult to keep, so if your dealer does not report problems keeping them in your local water, I would look first to improving your water quality.