ive just got a new tank 72l , i was wondering how long i shud leave it before putting fish in,, i have just filled with sand and water today, ive put dechlorinator and plants in, and brand new filter,,and heater are running , water temperature is 24 ,ive got my fish in my other tank ready to put in my new tank, just dont know how long to wait? also i got given a platy yesterday, i noticed it has 2 white spots , ?? , any ideas what they are,or how i shud treat it? if id have noticed the white spot on it, i wudnt have taken the fish,