i have an angelfish in a 10 gallon tank, along with 2 small goldfish, and a black bottom feeder. ive heard fish only grow as much as to fit the tank their in, but lately my angelfish has grown to about 6 inches from top to bottom of its fins. the bottom feeder has also gotten quite large, and they are both looking a little too big for the tank, and i was wondering if i should be concerned about getting a bigger tank for them, or if they are fine how they are,providing they dont grow any larger?

You should most definetaly look for a bigger tank. Goldies require at least
10 gallons minimum each. Goldies and tropicals should be kept seperate, due
to different needs. Try getting 2 29 gallon tanks and you should be doing good.

wow, had no idea goldfish needed that many gallons, i guess i can start my search for new tanks now, thank you for your help!

Make sure to have filtration for the goldie tank 10x's the amount of water.
A 29 gal tank would need 290 gals of filtration for example. Tropicals doesn't
need to be as much, but it shouldn't hurt?

You mean the amount of water being cycled per hour, right? Because if I stuck a filter meant for a 100 gallon tank on my ten gallon... well... Firstly, I don't think it would fit, and second, the suction would be so powerful that it would do in my fish.

Exactly. 10 gallons per hour of filtration per gallon of tank water.

this means a whisper 30-60 or model 3 filter that sucks 300gph for a 29 which is what I have