hey all i have 2 mollies that have fish disease? (fleshy looking spots on their bodies and fins) so i got them in a small tank for treatment in my main 20 gal tank i still have a platty, some danios and 2 gouramis i dont want to treat this water becuase a i have a few snail and shrimp and read online the meds are bad for them. will this tank be ok with no treatment and maybe just a water change?