We brought home our first Betta last week. He is currently in the 2.5 gallon Betta Mini Bow. We are using it without the filter as I read that it is too strong for a Betta. This left a large opening in the back. I was afraid that he could jump out of it, or that our cats could get to him through it, so I covered most of it leaving an opening of about one centimeter wide and a few inches long. I was worried that that wouldn't be enough air, so I also propped open the feeding door leaving a similar sized air hole on the opposite side of the tank. Does this allow for enough air flow in the tank? I was surprised that the lid did not have a bunch of air holes like the 1/2 gallon starter kit we initially bought for him had. Also, he can't get out of those size openings can he? If this setup doesn't work, any suggestions? I can't seem to find a similar sized tank with a bunch of air holes in the lid. How much air flow does a Betta need?