The mollies are Dalmatian mollies, I have 1 filter and there is surface agitation, the tank was left for a week before I put any fish in, the water was tested at the pet shop and there were no elevated levels of nitrate or ammonia, the beta isn't aggressive and the temp. Is 26 degrees celsius.
I have one Siamese fighting fish and two mollies in a 25L tank. The pet shop said they'd be fine but ever since I added the mollies they are constantly at the top of the tank and they won't come down. Are they struggling to breathe?