kuhli has very light coloration

[kuhlifan]

I have three kuhli loaches in my tank. One of the two is very small with dark black bands on a vivid tan body. The other two are both twice the size of the other one and have the same color pattern, but the colors seem more washed out. They aren't as dark.

They have a place they like to hide, and when they first come out, they are very pale, but after a minute, they seem to darken up some. Is this a normal kuhli thing, or does it indicate some sort of stress?

[Mark in Vancouver]

It's pretty hard to say without photos. You may have two different species. What can you tell us about the tank? How large is it? How long have you had these kuhlis? What temperature, pH, etc...?

[kuhlifan]

The tank is a five gallon and has been up for almost a year. It's never had any illness in it. My biggest mistake was in setting it up with decorations that make it hard to clean, but it does make it a haven for shy fish like kuhlis. Also, it's a little overstocked, but I'll fix that soon. Originally, I placed four neons in it, two guppies, the three kuhlis and an otto. It has lots of live plants in it, two thriving banana plants and a water wisteria that I frequently have to chop large portions off of to keep it from completely filling every corner of the of the tank.

The guppies, predictably, began to breed far faster than I could remove the young. At one time, I had well over 100 guppies in the tank. I finally managed to break the breeding cycle, and will be able to remove the last few extra guppies soon (I wait until they are big enough to catch but not big enough to breed). I've been stocking lots of people's tanks for them.

As for water conditions, I bought strip tests not knowing they are innacurate, so I don't know for sure what the conditions are. The ammonia tests very low, the water towards the hard side, the ph fairly neutral but nitrates and nitrates high. Part of that is because it's hard to clean due to the plants and decorations, not to mention trying not to vacuum a cloud of baby guppies up. I recently put a small water pump in about two inches above the gravel to keep the water moving and get more waste to the filter intake.

After posting yesterday, one of the larger kuhlis came out. He seemed pale at first, but then darkened up the longer he was out. Perhaps it was because he was adjusting to the light, but I'm not sure. I just thought I'd check to see if there was some experience with color changes like that, so I'd know if it was normal or not.

None of the fish are showing signs of stress, they all seem healthy and peaceful, except for a few male guppies that constantly pester each other, but that's normal.