Over crowded tank? :(

Question
I went to a goldfish forum to ask for advice getting the water clear. I was told I have a slightly over crowded tank and I should get rid of some of them. :( I have a Black Moore (that is now orange), a Calico Fantail, a small Lion Head, a very small Emerald Catfish, my mother just surprised me with 2 Apple Snails. They are in a 30 gallon long tank. I have a filter but am looking for a better one, they have one of those long air stones. Well, I always heard 1 goldfish for every 10 gallons, so do I need to get rid of some?

Answer
So you have currently, 3 goldfish...The usual rule for goldfish is 5 gallons per inch of the goldfish. You have just enough room in your tank right now for just the goldfish...depending how many inches they are.  This tank will not last them very long, quite soon you will need at least a 55 gallon tank. Usually goldfish end up needing a 55 gallon tank or larger just for themselves. They all get 12 inches long.  

While looking for a new filter you might want to buy one that is for the next level up...say instead of buying a 30 gallon filter, buy one that is for 60 gallons. Goldfish need a lot of filtration as they put of 5x the amount of ammonia as any other fish. This will also help improve your cat fishes chances at survival...Goldfish don't usually do well with others due to the fact that they end up poisoning the water with their own waste. This makes is super toxic if its not being cleaned properly or the filter is not adequate.

I would honestly try to rehome at least one of the goldfish this will give them more room to grow. Either that or purchase a bigger tank. You might be able to find a cheap larger tank on www.craigslist.com