My Clown Loches seem bummed out

[Vyache]

Hey everyone,
I'm kind of worried about my clown loaches. I observe them every day and their behavior just changed. They usually hide in a large cave under a rock most of the time and come out in droves when I feed them. Now I've noticed that only a few of them are coming out and the rest are under the rock breathing rapidly. One of the largest is wedged between the side glass and a power head and some are laying on their sides or upside down under the rock. I know lying down is normal behavior for some clowns but mine don't do it this frequently, especially with wide open mouths and rapid gill movement.
-I have 16 clown loaches in a 135 gallon tank along with several red tail sharks a fleet of bala sharks and a half dozen congo tetras. Reticulated cories patrol the bottom.
-None of the other fish seem to be in distress
-pH 7.0, Temperature 80F, Ammonia 0.0ppm, Nitrite 0.0ppm, Nitrate 40ppm
-I frequently treat the tank with a herbal medicine called Prevent Ich. I think that it's organic components contribute to higher Nitrates
I know that high nirates can make it hard for fish to get oxygen, so this is my primary suspect. I'm going to do a series of 15% water changes throughout the day.(Any more and I'd have to unplug my power heads, which are a pain to reprime)

Anybody else have an opinion? I've had clown loaches die of what I suspected was copper poisoning after treating the tank with Aquarisol but I haven't added any chemicals except the Prevent Ich.

What other things could cause low oxygen?

 

[Vyache]

The answer shows itself

It's amazing how we figure things out easier when we write them down, at least I've found that every time I post a problem message I usually figure out the answer right before I hit "post". I'm pretty sure nitrates are a problem in the tank. I've also determined that my tank is over stocked. It was just fine a couple of weeks ago, but all my fish were purchased when small and every one of them has grown quickly since I got them. I need to move some over to my dads house. He has a 240 gallon that has only a few fish in it right now.

 

[colesea]

The formation of pockets of anaerobic bacteria in your gravel. This is the bacteria that is responsible for decomposition and give marshes that funky rotten egg smell.

Do you have a piece of silver jewelery? Tie it to a string and then put it in your tank. If it tarnishes when it hits the bottom, you have anaerobic bacteria in your gravel. You can remove the tarnish by lightly scrubbing your ring with toothpaste.

Also the nitrates will cause methehemeglobin formation. This prevents blood from carrying oxygen even if there is enough oxygen in the water. Fish will breath heavily as if they are out of breath because they are not getting enough oxygen exchange across their gills and into their blood because the.

I think your 15% water changes should do the trick, try to lower your nitrates to at least >5ppm. When removing the water, use a gravel vac and try to dig as deep as you can into your gravel (provided you don't have sand or rooted plants) to promote aeration within the stones. Space your water changes based on how many times your tank cycles within an hour. You want the new water to be well mixed with the water in the tank before you change again so that your fish don't go into shock. That should be at least one tank cycle between each water change, or if your tank cycles more than once an hour, space your water changes as least two hours apart.

Good luck.
~~Colesea

 

[Vyache]

Excellent advice! You anticipated a question that I was about to ask, that being, should I just change the water and try not to stir anything up or gravel vac and try to get gunk out. Thanks Colesea, its always nice when one can get an almost immediate answer to a posted question.

-Vyache

 

[Vyache]

Another problem/solution

Colesea mentioned the turnover rate of my powerheads and that got me to thinking. I checked and the little tubes that "siphon" air into the water were in need of maintenence. Two of them needed their filters cleaned and the other one never had a tube since I got it used. I used a little piece of aquarium tubing, it doesn't quite fit right but it will do for now. Ok so now I have a lot more bubbles going into the water and therefore a lot more surface turbulance. There should be more oxygen in the tank soon! I also turned the heater down a little since colder water holds oxygen better. It was set at 82 to help prevent ich because I recently added a couple more clown loaches. Its now set for 78. Hopefully thats cool enough to hold more oxygen but not cold enough to cause ich. Anyone know the relationship between water temp and oxygen? I'd love to see a chart or something if you can point me at one.

 

[colesea]

I don't know the exact relationship as far as what the ppm of oxygen is at certain degree temps. Just the general trend that warm water holds less O2 than cold water. Somewhere in my closet is a scientific book that will explain it, but right now I'm too tired to go look. Try some water chemistry websites or college department websites and see if you can't find some proff that posted lecture notes. I'll see what I can find tomorrow morning.
~~Colesea