looking for some advice! i have a 180 litre tank with a variety of fish, 4 gourami's 2 bala sharks,4 mollys,8 cardinals,3 rainbow tetra,5 black phantom,4 red phantom,4 cherry barbs,2 swordtails,2 glass catfish,2 platys and 4 bottom feeders. when we started the tank up never lost any fish for...