fish size

Question
Hi Bethany,
About a year ago i got a 10 gallon tank and put 3 platys and 3 guppies. The platys i got were about and inch long. after a while my tank was filled with lots of guppy and platy fry. now most of them have matured but are not as large as the original fish. it seems like there growth has been stunted. Like i said earlier, my original platies were about an inch long, now the new one are only about 1/2 or 2/3 that size. it's been about 9 months, so are they done growing? i was also thinking that maybe the water temperature had something to do with it. mine goes from about 75 degrees to 80 degrees. i was thinking either that or that maybe my tank is too crowded. i probably have about 20-30 fish of ALL sizes. from newborns to the adults. any information will be greatly appreciated. thanks!!!

Answer
Angel,

Oh my goodness! 20-30 fish in a 10 gallon tank? That's a very overcrowded tank. The lack of space has probably stunted their growth. The rule (typically) is about 2 inches per 1 gallon of water (so in a 10 gallon - five 2 inch fish!)This is hurting your tank severely. It's going to cause 2x a week 25% water changes (filter or no), stunted growth, health issues (diseases spread VERY quickly in an overcrowded tank), and possible cannibalism. I suggest trying to pick out the male from the female guppies and platys. You cannot prevent fish from mating, so this is bound to happen again and again. My suggestion is to find a pet shop who is willing to take the extra fish off your hands and help you pick out males from females (my tank has 2 female platys, 2 male turquiose guppies, 2 male neon tetras, and 1 "Sucker" fish). Male Platys will be aggressive toward one another without any female to mate with, so I recommend the female half of that species and male guppies tend to be more gorgeous, so that would be my choice.

For your 10 gallon tank, I recommend no more than 6 fish at a time.

-Bethany