Impulse Buy, But Now I Know Better

My friend wanted to adopt a puppy from Petsmart, so we loaded up the kids and went to take a look. Turns out, we were a week early for the pet adoption, so we decided to take the kids for a look around at the birds,reptiles, and fish. Well I ended up purchasing 2 bettas and a 1 gallon divided tank with filter and light. I also purchased water conditioner, food, and that was pretty much it. Upon getting home that night I started doing my research and quickly realized that I made a huge mistake. I purchased another 1 gallon tank so they would at least have their own space. They could see each other through the divider. I purchased heaters that stay at 78 degrees F. They did pretty well in their one gallon setups. They were in there for 2 months and then I was telling my friend about how I needed bigger tanks for them, and she decided as an early Christmas present she would get me two new tanks. I now have two 3.5 gallon tanks with filter, light, heater. I have read that tanks this small are extremely hard to cycle and then water changes throw the cycle out of whack again, so I have just been changing the water twice a week. I check my ammonia levels as well as my other water parameters regularly as well. Their tanks are decorated each with 1 silk plant, one cave, and half an almond leaf. One tank has river rock for substrate and the other has pretty glass marbles for substrate. They seem to be ok, but there are a few things I am concerned about.
1. Bluey, my male veiltail has a lot of curling on his fins. What causes this, can it be corrected?
2. Luna, my male half moon has been caught biting his fins. He starts to heal, I can see new growth, then next thing you know, he bites again. I keep the light on a dark colored setting, like red, blue, green. I have rearranged his tank a few times, I have made him a hideout spot close to the top of the tank using a pvc pipe joint. Just drilled a hole in it and put a suction cup on it and stuck it to the wall. Is there anything else I can do to stop him from biting his fins?

 

Curling at the ends is nothing to worry about. I read somewhere that it's because they were kept in high pH at some point (not sure about the accuracy of that but either way you don't have to worry).

Some bettas are just tail-biters, usually the ones with longer, heavier tails. They drag the fish down and make it hard to swim so the betta will try to bite it off. There's not much you can do except keep the water super clean so it doesn't get infected.

 

I don't know about the curling, but check both of them for signs of fin rot. For a floating hideout I use the floating log. Hope this helps!

 

I'm not sure what filter came with you tank, but you might check to make sure that the flow is not too strong. That stresses bettas out and sometimes they do tail bite to relieve the drag from the water through their long fins. I would also check to make sure something doesn't have a sharp edge and is tearing the fins.

 

Sometimes fin biting just can't be helped, I know my halfmoon won't stop.

 

Fin biting can be caused by too much filter flow, is there a chance that that's the issue?