Should I get a 4th fish + B.Q., thank you everyone!?

More platies or guppies, smaller cories, otos, kuhli loaches, gourami, or many others can go in a 10 gallon tank.

I've never followed the inch per gallon rule. If that were true, the most a 10 gallon tank could hold is 5 endler guppies (smaller guppies, max out at 2 inches.) But, the truth is, you could have a lot more endlers than that!

And, in a 20 gallon tank, acording to the inch per gallon, two 8 inch fancy goldfish would work just fine. You could even squeeze in a small 4 inch one! No. Not going to work. Or, if you want another example, a clown loach and an angel fish or two would, according to the inch per gallon, be alright in a 20 gallon tank.

So, I don't follow it. I never have. It's a good starting place, though.

Wait for the tank to fully cycle before you get new fish.

And, make sure you use a quarantine tank for your new fish so you don't end up with something like ick in your tank and all of your fish die. I put mine in a seperate 10 gallon tank for at least two weeks. If ick does pop up (which happens more often than not) I just crank the heater up to 88 degrees and restart my 2 week waiting period.

Platies are community fish. Don't mix them with larger, more active fish. Don't mix them with coldwater fish. And, don't mix them with aggressive fish. Other than that, you're pretty much safe with any other type of fish.

Forget the "inch per gallon" rule, although it gets somewhat close with 2" fish, it's NOT a good way to plan you tank stocking

Having said that, you probably can get one or 2 more SMALL fish in there.

Swordtails are compatible with guppies and platies, but they grow a bit big for a 10 gal tank, 4-5" max. That's a bit too big for that tank.

Main problem is that most other fish that are suitable are schooling or social, so you need a group of them. And that takes up most of a 10 gal. Not enough space with the fish you already have.

One suggestion would be a dwarf gourami. Or, there is no reason you can't get another guppy or platy, just choose a different colour.

This page is a better stocking guide than relying on any 1" rule.

http://www.aqadvisor.com/AqAdvisor.php

It suggests that adding a dwarf gourami would take your tank to 82% full, which is fine.

Adding another platy gives you 79%.

Anyway, you could get another fish in there if you want. But you don't HAVE to fill a tank. Understocked is easier to maintain and healthier for the fish. If you are happy with what you have, that's fine too.

Ian

Don't listen to these so called experts .. I have 5 cichlids and 4 black fin sharks and a pleco in a 20 gallon for almost 2 years now and everything is great so do whatever u want