I have just bought 3 khuli loaches (the last ones in the store).

I floated the bag and added tank water slowly, they have been in the tank for a couple of hours now.
They are extremely active. They are swimming up and down the tank at a million miles an hour like they are trying to escape. They stop for a sec, then off again.

Is this normal?! Everything i have read says they tend to be very shy and hide when first introduced.

The tank was already cycled and had a water change before i bought them so the stats are good. Tank has sand and there is bog wood for them to hide under.
Only tankmates are 2 sterbai cory's and a couple dozen neons.

How do i tell if they happy or really stressed?

Thanks

It is normal.

Kuhlis can be very active reacting to new tank, or a large waterchange, or occassionally even a change in atmospheric pressure. May take a few days to settle down.



They are stressed, of course. One way to tell if they are healthy or not is to watch them land, if the landing is controlled, they are probably ok, if they "fall down", expect problems.