fishes compatible with goldfishes and mollies?

Well, goldfish and mollies and gourami's are NOT compatible. Goldfish are coldwater and need a thirty gallon MINIMUM for a single fantail alone. Your calico goldfish need....like 75 gallons per fish. They do NOT stay small, if kept in small places they will on the outside, but their organs will eventually be crushed from the stunted fish. They also must not be kept in waters warmer than 68 degrees and prefer it even cooler. Goldfish in warm waters result in a very fast metabolism that will eventually fry their systems and kill them.

Mollies need to be in groups of five, and have a bioload that almost rivals the goldfish, but not quite. The mollies and gourami's are also warm water fish. Both of them require their water temp to be 78 degrees...well, mollies like it between 78 and 80 degrees, dwarf gourami's like it to be 76-78 degrees. Keeping them in colder water, even water as warm as 74 degrees, can and will result in sick fish, especially with your mollies and goldfish. Your mollies will get sick easier and catch parasites, and have a much higher chance of getting fungal and bacterial infections.

Gourami's should also not be kept in groups unless you have one male and one female, or a LOT of space, which you do not have. They can get aggressive when they're older, though you sometimes get lucky raising them together. And if you have a male and female and they breed, the male will try to run her off and kill her if she doesn't, or can't leave, as well as do the same to other fish in the tank.

I'd suggest you take back a gourami and ALL of your goldfish, and get two more mollies.

Keep in mind, fish need space to swim and to grow, not to just sit and be pretty. The bioload in that tank has to be out of this world, if you got a test done, you'd most likely have VERY high, and very fatal levels of ammonia and nitrates and nitrites.

With proper stocking, you will only need to change about 30% of the water once per week with a good quarter to half vacuum of the gravel, different spot each week. =) Right now you have too many fish, and the wrong types together! You could clean out the tank daily and still have extreme ammonia within hours, and over-cleaning is just as deadly as an uncycled tank.

Live plants are always good too, they help filter and keep the bioload down a bit, but you still need your regular weekly cleanings, they just add in some extra help!

Goldfish are not compatible with mollies or gouramis. Goldfish are cold water fish while mollies and gouramis are tropical. The 4 goldfish are also over stocking the tank. 4 fancies need at least 60+ gallons but the larger the better.

You will either need to rehome or return either the goldfish or tropical fish and upgrade the tank for the fish you decide to keep. If you want to keep both goldfish and tropical fish you'll need two tanks.

Instead of adding maybe, subtracting or dividing? Goldfish aren't what you would consider compatible with tropical fish. Goldfish are cold water fish and have different requirements. A pair of Fantails will need a 40 gallon aquarium. 29 gallons for one another 10 for a second goldfish. Also needing double filtration. As well as your Calico goldfish. As for water changes, 20% a week would work.

Whoa whoa whoa... 4, let me get this straight, FOUR GOLDFISH IN A 25 GALLON? WOW! just 2 goldfish in a 25 is overdoing it. You either need to get a 170 gallon tank if you want to keep those goldfish or you have to get rid of them! Goldfish dont grow to a appropriate size for the tank, they just grow and grow and grow. You CANNOT get anything else. I repeat NOTHING. Your tank is already 500x overstocked. You may not think so, but goldfish are very different from your typical tropical fish. Goldfish are very messy too. If you choose too keep them and not get a larger tank (not recommended) do 25% water changes weekly. But on the other hand, if you choose to get rid of the goldfish, you could get tetras, platies, more mollies, guppies, danios, etc smaller peaceful fish.

I hope you can work something out.

Message through my account if you need help with anything.

EDIT: Goldfish are also cold water. They should not even be with mollies or gouramis. Not to be rude, but im surprised all your fish aren't dead yet.

No it is already very overstocked.

Also goldfish shouldn't be kept with mollies or gouramis because they need different water temperatures.

They will most likely start to die if you don't split the tanks and put a heater in the Molly/gourami tank.

Overstocked

you should either take out the goldfish or tank out the mollies and gouramis.

mollies and gouramis are tropical fish, meaning they require a heater. but goldfish dont.

if you keep the goldfish, here are some compatible fish: bubble eye goldfish, black moor,weather loach, oranda goldfish, koi carp, guppies, white cloud minnows, guppies, plecostomus, fancy goldfish.

If you are keeping the tropical fish, you can get any other tropical fish, but no angelfish.

before you do anything, get a bigger tank.

Agree with jamie!