setting aquarium up.

Question
hey linda, we've spoken quite abit haha, my moms buying my an aquarium for christmas its far away but she said she may be getting it sooner, she said not a big one, a medium one.. so would a 20 gallon be ok ? also if so what fish can i stock in it.. i was thinking,
2 sunset dwarf gouramis
2 female betas
a school of tetras maybe
and some mollies and maybe some loaches for the bottom?
if i can add more please tell me (:
also if the 20 gallon is too big if my mom thinks so what can i put in a 15gallon?
thanks

Answer
Hi Alex,
An aquarium can never be too big..lol  If your Mom wants to buy you a 20 gallon tank, then that would be a very nice Christmas present.  
If you go with Mollies, then I would recommend that you get different kinds of Mollies, and no other fish.  Mollies need alkaline, and salty water.  This means that we must add 1 teaspoon of sea salts, or aquarium salt to 2 gallons of water for them to be happy, and thrive.  Mollies will not last very long in water that has little or no salt.  Many Mollies finish there lives in salt water.  They are pretty fish, and come in a variety of colours.  There are also the Balloon molly which are different.  They can be mixed with the regular, and sailfin molly.  They look nice in a tank with silk plants.  They are vegetarian, but can have bloodworms, daphnia, and brine shrimp now, and then.  You could put 10 mollies in your tank, but remember mollies are livebearers, and many little ones will survive.  Maybe it would be best to have 6 to start off with.  One males, and 5 females, or you could buy only females, but this will not guarantee that they are not pregnant.  Females may have up to three spawns after being injected by the male.  

Sunset gouramis are so cute, and yes they would look nice in a 20 gallon tank, with a school of tetras, maybe 6-8 neons, or 6 emperor tetras.  The emperor tetra is a pretty little fish, an little bigger than the neon.  As for female bettas, in my experience with them, they are just as bad as the male.  One female will dominate the other, so it is best to put just one in a tank.   I have yet to see an aquarium where no fights broke out between females.  Some of them are really wicked, it is always a throw of the dice when it comes to bettas.  I prefer keeping them alone in a five gallon tank.  They are really loners, clever little fish, but best kept alone.  You can add 4 little cory catfish, two platys, and if you omit the betta, you could put in one Angel fish. When buying sunset gouramis, buy females, because if you buy a pair, the male will always harass the female whether she has eggs or not, and seeing as these are timid little fish, the female would eventually die.  Buy females, and you won't have any problems with them.  You must have plants in the tank, either real or silk, and a real floating plant for the gouramis.
So this would be one choice:
2 sunset gouramis
a school of tetras 6 or 8 depending on the tetra you will buy
1 betta
2 platys
4 cory cat fish
4 kuhli loaches

and if you omit the betta, you could add one Angel Fish, or instead of the betta,or Angel, you could add 2 pearl gouramis.  The pearl gouramis is the gentlemen of gouramis, and a beautiful fish.  They are also very timid, and would go well with the sunset gouramis, but you must have a floating plant for these fish.  The pearl gourami grows to about 4 inches.  I would also buy two females.  The females are just as pretty as the male.
Remember that you must let your water cycle before adding a fish.  Buy a used sponge to start of your new tank that fits your filter.  Let the water filter for at least three weeks, and add water that has evaporated.  When your ammonia level reads zero, or safe, and your nitrite level reads zero or safe, and your nitrates are low, then you add two fish, and you wait one week.  Do a 25% water change, and check your water again, if you water chemistry is right, add another two fish. Do this until you have the fish you like in your tank.  Never add all the fish at once because your water chemistry would change killing off all the fish.  You can buy these small test kits at your pet store or Walmart, and they are always handy to have.  Do 25% water changes every week, and feed your fish a varied diet, and everything should go well.  Feed the bottom fish, sinking pellets, and wafers.  Little corys love these.
I would also like to mention...when you clean your filter, always clean your sponge in water that you have removed from your tank, and not under tap water.  This is to keep the good bacteria in your sponge that tap water would kill.  A sponge is good for a very long time, until it is old, ragged, and falling apart.
I know you will be a good fish keeper, and I hope this helps.
Lynda