I noticed one of my dalmation mollies had been acting weirdly - it was always sat at the bottom of my tank (160L) - occasionally moving when my other mollies came to disturb it. I'm assuming it's male, but if it was a pregnant female would they sit at the bottom? Although it could be just be 'fed up' with the other mollies always harassing it. It doesnt look injured or diseased. Anyway, I set up a quarantine tank (20L) - I added filter media and water from my main tank, and now the mollie is eating better and swimming more. Is what I have done the right thing to do? thankyou! 
