Originally Posted by PhilipPhish
I really do recommend a bigger tank if you want a puffer fish... perhaps 5 or 10 gallons with a heater and very strong filter.
If you are looking to stock a 2.5, I highly recommend a male betta or wild/fancy/endler guppies.
Posted via Mobile Device
Don't get too strong a filter. They'll get sucked up. I have an Aquaclear 20 on a 10 gallon tank, here you can see the sponge I put on the water intake to stop them from getting vacuumed. (Aquaclear's have adjustable water flow and mine is not running full blast)
For the record, with 2 in a 10 gallon, I just do my usual 25% water change once a week when I do my other tanks, and I have 0 nitrites, 0 ammonia, 5 nitrates. They are messy eaters, but if you feed them one worm at a time, and don't overfeed, they're not that bad. I also have a lot of plants in this tank, which helps.
As has been mentioned, however, keeping one in a 2.5 will require more water changes. But I would think 30% twice a week would be plenty. (I don't know for sure, never kept anything in a tank that small).
I keep a Betta in a 5 gallon and 25% water changes once a week keeps the water at the same parameters listed above. A single DP does not need a 10 gallon tank, by any means, but a 5 would be infinitely better than a 2.5 (well, maybe not infinitely, but certainly twice as good, lol)
People keep pushing Bettas because they're the best fish for your size tank. I'm not a huge fan, but I have one because I had a 5 gallon and not much else to do with it. I actually like the darn thing now.
Mary Poppins, our male Betta. My son has gender issues.