Why are my fish dying?

**CrazedMichael** · 12-09-2012, 12:05 PM

this may be a long shot, but how tall is the tank? Cos Cories need to come up for air now and then and maybe they cannot reach or they cannot find their way up due to things being in the way. You said you feed every 2 days, so possibly they are getting picked on everytime they come up for air by the other fishes. This is all extreme 'what if....' and are highly unlikely.

One overlooked possibility is lack of oxygen in the water, but as you said you have an AC110? That, installed correctly, should be enough to agigtate the water for gas exchange.

So i'm thinking maybe it's the well water. It may be chlorine-free, but it could have other contaminants in it. Is it possible to have a sample of well water tested?

**Goes to 11!** · 12-09-2012, 12:16 PM

Originally Posted by CrazedMichael

So i'm thinking maybe it's the well water. It may be chlorine-free, but it could have other contaminants in it. Is it possible to have a sample of well water tested?

True, Metals maybe or any number of things are possible on that front...

**talldutchie** · 12-09-2012, 12:33 PM

That should have hit the pleco just as hard

**Goes to 11!** · 12-09-2012, 12:54 PM

Yeah understood ... I was just musing out loud...

**cj5_dude** · 12-09-2012, 02:50 PM

The substrate is standard aquarium gravel you buy at any fish store. The AC110 agitates a lot of water and I have an air stone in one corner to add extra so there's plenty of gas exchange going on. The tank is a standard 29 gallon tank so it's 18.75 inches tall. I would think if it was the well water it would have shown issues a long time ago and not 2 months or more after using it, but I could be wrong. I'll re-test the nitrates and get back to you on that.

**Dave Waits** · 12-09-2012, 04:18 PM

Originally Posted by cj5_dude

Back on topic...

I don't hardly test at all. My cycle ended on 10/16/12 and at that time I had a nitrate reading of 10. I did a nearly 100% water change at that time and when I tested again on 10/25/12 I had 0 nitrates. I haven't tested again since until today. I am following the instructions of the test to a T and they are not expired. I test much more frequently on my saltwater tank but don't worry as much with the freshwater. There are no live plants in the tank, just tons of plastic ones.

It's very possible my nitrates were higher between 10/25/12 and yesterday or two days ago whenever I did the water change (can't quite remember) which would have been around 12/06/12. I tested again today and those are my numbers. I feed every other day to keep rotting food to a minimum and only feed what they'll eat in 30 seconds or less. The cardinal tetra's have grown a ton since I've put them in two months ago and the gourami may have grown I just haven't really noticed.

If there was a bump in the numbers after adding the pleco I wouldn't have a clue since I didn't test.

A nearly 100 % Water-change? You may have destroyed your cycle right there. If all your readings have been 0 ppm since then this may well be your problem. Just thinking out loud here but, it seems to me that this could not have helped your tank. This also could have damaged what colony you had built up in your filter-media.

Still don't understand all I should about all these water-changes people do now but, I do know they lengthen a cycle with them so, a change of that magnitude could have really messed things up.

**cj5_dude** · 12-09-2012, 05:00 PM

The large water change after the end of the cycle had no affect, because the nitrifying bacteria doesn't live in the water and was residing in the filter. All I did by doing that large water change was to drastically reduce the nitrates in the water.

I re-did my tests and made sure to shake the nitrate bottles extra hard and extra long and guess what...I got different results.

Ammonia - 0
Nitrite - 0
Nitrate - 5

So I had a false nitrate reading yesterday.

So why are my cory's dying?

**jeffs99dime** · 12-09-2012, 05:04 PM

Yes, but the near-100% water change may be stressing the Cories to the max. They don't handle large changes well at all. They also become easily stressed if not provided with ample places to hide during these changes.

**KevinVA** · 12-09-2012, 05:06 PM

Could be you have bad stock from inbreeding. Or, it could be contaminants in your well water that the corys are more susceptible to than most other fish. Could be lack of oxygen. Can you post a pic of your tank?

**jeffs99dime** · 12-09-2012, 05:09 PM

[QUOTE=Dave Waits]A nearly 100 % Water-change? You may have destroyed your cycle right there. [QUOTE]

That will not destroy your cycle. It will, however, change your water parameters drastically in the tank.