Fish Questions UPDATED!!!

Okay, today my mom recomended we go to our local fish store and I am so excited because it looks like we're going to be bringing home some new fishies today! and a new betta tank! But here's my current situation: I have a 5 gallon hex aquarium with a filter, light, and heater and there used to be 4 black skirt tetras and 5 neon tetras, but something in their water went weird so most of them died and now we have to add enzymes. I have my betta Prince in a tiny little bowl because his 1 gallon very very badly designed cheap tank was infested of some little water bug (probably because I left my window open so some bug laid eggs in there) so we had to move him which nearly killed him. I'm going to bring a water sample from my 5 gallon tank to the store today to make sure water levels are good, and if they are, we're going to get some more fishies! I will also probably bring a sample from the betta tank and if all goes well I will be getting a new betta tank too! But, the tank I looked at online was 2 gallons and got really good reviews. I always hate to see my lonely betta and was thinking of getting him a tank mate, I know I can't get another betta or any other colorful fish, so any suggestions? I will definately give you guys an update when we get back (but we're leaving in like 6 hours) and maybe will upload pics!

A 2 gallon tank is really too small for much of anything. So is a 5 gallon hex. A hex tank, because of the surface to water ratio, should be stocked as if its only half the size. Your 5 gallon hex provides the same space ratio as a 2.5 gallon square tank. You wonder why the water quality went bad. You'll need a filter and you'll need the tank cycled if you want to add any other fish to the betta tank. You really should have a filter and cycled tank for bettas too. They breath air, yes, so they don't need the oxygen a filter provides. But they do suffer from the ammonia levels that build up daily before you change the water. If anything, you could add one platy to the betta tank.

I was thinking that the 2 gallon aquarium (which is square-ish and has a filter and a heater) could house my betta and a small tank mate, possible a little bottom feeder or snail of some sort and that the 5 gallon hex aquarium (which also has a filter and a heater) could house like my neons and 2 mollies or something. The only reason my betta is in the un-filtered bowl right now is because some bug laid eggs in the filtered one (probably because I turn of the filter off at night because it's soooo loud). Don't worry, I know the one inch of fish per gallon and am confident the ammonia levels are back to normal (but I'll still have the water checked). I'll be back tonight with an update on how the day goes.

i dont know if this helps, but try washing the tank with vinegar. it kills all the germs. make sure to rinse it out properly. also, i have had a fighter with some zebra danios, and that worked well. careful though, they are jumpers, and they are pigs. make sure ur betta gets some food too.

UPDATE: Okay, no fishies for me, but instead a message to IRescue452: you were right! The betta bowl tested extremely high for ammonia levels and the hex 5 had extremely high ammonia and nitrate levels, so right now I'm adding enzymes to their water. I decided to not get any more fishies for the hex 5 and when the neons go up to RB I'll just throw out the hex 5. But, for Prince the betta, he got his own 2.5 gallon aquarium with his own filter and a live plant, some little fake plants, a nice rock, and some blue gravel. Although I'm out $65 I definately think it's worth it! I'll update once he goes in the tank (after it's cycled) and then I might get him a little tankmate!