Q about a Gastromyzon spp.

[VinsonMassif]

I have 6 Gastromyzon spp. and Sewellia lineolata in my 80g. I finished a two week salt treatment for Ich. on Friday. The temp was raised to 30*C and 2tsp/g of salt was used.

Since I started the treatment one Gastromyzon loach went blotchy then pale, and is now white. All other HSL are regular colours. No fish in the tank is showing any sign of stress, or appeared to during treatment.

The white HSL has no sores, wounds, growths. It is eating and behaving normally as far as I can see.

The parameters are: ammonia, nitrite undetectable, nitrate 5ppm, pH 6.4, KH 2.

It is a planted tank and there are a lot of stones and flat rocks in the tank.

After Friday, each day I did part water changes: 20%, 20%, 50% for each day after that to remove salt.

Can anyone enlighten me as to whether it seems my HSL is suffering an ailment? Or recommend a course of action, or anything I should watch out for please?

[Diana]

You might have lowered the salt level too fast, but I am not sure. Pale color is often a sign of stress, but does not always indicate the source of stress.
Are there some social issues going on among these guys?
Any other symptoms?

Salt raises the TDS of the water. This kills the parasite by dehydrating it, but the fish start adapting to it, even in as short a time as a couple of weeks, and need time to adapt back to the lower TDS level of 'no salt' at the end of the treatment.
It is harder for the fish to adapt to the lower level of TDS than the higher level, so the salt removal needs to go slower than raising the salt level.
I would do enough water changes to keep the nitrogen levels under control, but work on lowering the salt level over a period of about a month, even though raising the salt level was done in just a few days. But perhaps I am just a little conservative in this. Perhaps lowering the salt level can be done faster.

[VinsonMassif]

Sorry I didn't reply sooner. Life got in the way again

There is some tussling going on. It never seems to be prolonged, on individualised. I do watch them a lot.

I never knew reducing TDS had such an impact. Possibly I did reduce the level too much, too quickly.

That HSL is still a little pale, but far from white. I have not done a water change in the last 4 days. I can reduce the frequency some. My nitrates never seem to be an issue. I measure weekly and they hover 5 or less. I have held off on dosing the plants in the last week, am sorting things out before I continue with a plan. Trying to do what is best for the fish

Thanks for that.