I've had my betta for a little over a year now and he's been fine this whole time. This week I moved him from a one gallon bowl to a 5 gallon tank. There is no filter, but I've been doing water changes. I am using sand for substrate and he also has a snail in there with him. Last time I looked in on him (this morning) he was fine but now he seems very bloated and he's spending all his time at the top instead of swimming around. I have no idea what would cause this, I just did a water change (25%) yesterday and it had only been a day before that that i did a 100%. Is it possible that this could be from the sand (never used it) or that he ate the snails algae pellet? I only feed the betta 3 pellets a day, so i don't think he could just be overweight. His scales aren't sticking out at all either so I'm not sure if it would still be dropsy? Any help is welcome, thanks!