Hi,
I am not familiar with Molliebrite..maybe we dont have it in the US or maybe I just haven't come across it..but to answer your concern.
You didnt mention whether you just got your mollies or whether they started behaving this way suddenly.
If they are brand new, give them a day and see if it is just them adjusting to new surroundings.
If not, the only thing to do is trouble shoot.. is your water on the hard alkaline side? If you live in London, I believe the water is hard and alkaline and this is perfect for Mollies.
Mollies like warm water, what is your temp? I find mollies do well in water of about 78 degrees
Mollies also love veg.. do you have some spirulina flakes to feed them? sometimes they can get constipated.. try a high quality green food like spirulina
Have you tried adding freshwater aquarium salt to your tank? Mollies love
salt and sometimes it can really revive them.. try it if you haven't it can only help them.
Personally, I wouldnt keep Mollies without salt. If you choose to use salt [and I hope you do] remember with your water changes to add the appropriate amount of salt to replace what you took out.
The could be suffering from a mild bacterial infection or just osmotic stress if they are new.
good luck, mollies are great fish..hope you enjoy them.
