most people are going to tell you you need lots more tetras. recommended is about 6 or more a piece and I will agree to an extent although I tend to have better results in my community tank with 3 each. I've had as many as 9 neon's and they never stuck together so what's the point in having that many? The reason for their numbers is security in schooling but this is really not necessary unless there is a threat that keeps them uncomfortable such as more aggressive larger fish or lack of hiding places in the tank. I would add another neon, 2 more black neons and another glowlight so you at least have a small group. As far as additional fish, I would probably get a pair of cory catfish and you could add some more tetras such as cardinals, bloodfins, greenfire, rummynose, pristella, etc. I would tend to stay away from tetras that have the taller shape because they tend to be a little nippy and get larger than those others and they could cause a little too much stress in a 12 gallon. these tetras would be like serpae, blackskirt, lemon, von rio, etc. If you want something other than tetras, you could go with some livebearers such as guppies, endlers, platies, swordtails, mollies etc. the problem with these is that they will successfully breed and overpopulate your tank fast so unless you had the ability to get rid of the fry, you could run into problems. Another fish that I think might work well would be some sort of smaller killifish. they are extremely colorful and there are a lot of them that stay rather small. the downside is their lifespan is very short due to their natural lifecycle. In the wild they mature very fast and lay eggs. Then their home pond or whatever body of water they are in will dry up leaving the eggs to dry out. Once the rainy season returns it will reactivate the eggs and they hatch and start all over. I believe most killi's live about a year before they die but I have yet to keep any (I'm planning to get some in the next couple weeks to try and breed). you have several choices, just make sure you research what you want to get before making a mistake. KYle
