loaches dying again!!

[Brhino]

It's happening again! One week after I lost two clown loaches immediately after a water change I'm losing three more. They're still alive, lying on their sides, breathing normally. One is making periodic dashes to the surface, but the other two aren't moving.

I am 100% sure I remembered prime this time.
I am 100% sure I matched the temperature well this time.
No signs of distress at all from the danios or the pleco or, for that matter, the other three loaches.
I have changed 4 other tanks this week without incident so there is nothing wrong with my source water.

I don't understand it! My poor fish...

[Cliff]

Brhino, I am very sorry to read about this

I wish I could be of some help here

[Brhino]

okay, I did find one dead danio stuck to the filter intake... that's one out of at least three dozen. Two of the loaches are stone dead, the other is still alive but not breathing much. That leaves three apparently unharmed survivors hanging out in their caves, with, by all appearances, nothing wrong at all.

[Brhino]

a few more notes:

The problems did not start IMMEDIATELY. I watched them for 5-10 minutes after I completed the water change, turned the filters back on, etc. No signs of trouble. Went around the house to feed all tanks, which took another 5-10 minutes, and came back to three fish lying on their sides.

I moved all three to a breeder box so they'd be ready to remove but not quite taking them out on the offhand chance that they could recover. The last to go had enough strength to try and jump out of that (but I had it under the lid) a few times and then stopped trying. After it was no longer breathing its fins were swill twitching faintly.

no unusual markings, discoloration, or anything else. As I mentioned last time, a heavy slime coat but I don't know how that compares to the slime coat of a healthy loach.

[Lady10Godiva]

Wow that sucks. Last year I lost 5 of my small clown loaches due to ich. I dont know why but I felt way worse when they died than when other fish have died.....probablt do to their personality.

I hope you can come up with some answers. I know you really want them to be the feature in your megatank.

Good luck.

[Brhino]

last week somebody suggested that 50% water changes are "too much" and that started a big debate about such things.

At this point, I'm open to any theories. But... I got these fish at the end of 2011. They went through over 50 water changes, all around 50%, with no trouble at all, and only now are they dropping dead. That doesn't make sense.

[Honey Badger 1]

Brhino, try this site to help diagnose the problem; http://www.fishyportal.com/diag/ I checked heavy slime coat and fish lying on the bottom on one side and it came up with heavy metal poisoning, but it seems if that were the case all the fish would be affected. Maybe going through the check list you will see other symptoms you didn't realize.

[Brhino]

Thanks mommy. Nothing seems to fit just right.

I had a bit of a thought. This tank's in the basement, so when I do water changes I use a different tap than the rest of the tanks. So perhaps there's something wrong with the tap. But... I also keep my fry tanks down there, so water from that tap has done changes for those tanks, and you know how sensitive fry are...

Seems like any theory I come up with immediately has a reason why it can't be right.

[Honey Badger 1]

You could be on to something there. I know it's a long shot, but maybe you should try the next water change with water from upstairs. I know fry can be sensitive, but I have a constant cloud of texas cichlid fry in my tank these days and it seems the only thing that kills them off are the other texas cichlids. There could be some nasty lurking in the basement pipes that the loaches are susceptible to but the fry are not.

[KevinVA]

There could be a slight to significant change in hardness, if you have metal pipes that are corroding in the basement, thus your tap is different and adding more minerals to your water than your fish are used to, causing them to go into osmotic shock.

Just a thought. Test your water hardness (and pH) and see if it differs greatly from your other tanks.