Dwarf Puffers
The above is a good website by our very own jread thats worth a look.
I tend to keep my puffers in a tank with a sand substrate for a couple of reasons: They're very messy eaters and sand it MUCH easier to clean IMO; I've added malaysian trumpet snails into the tank for them to feed on (yeah I know some people think you should use these as it can break they're beaks but so far I've never had a problem, if it does get a little jagged then continual eating will wear it flat again!); mine often like to hunt and "jab" at foods, sand is much kinder on the fish. I've got some banjos in with mine which which need a sand substrate.
Dwarfs generally need 3 gallons per fish, you can get away with slightly less than this if you've got good filtration but generally I'd stick with the 3 gallon mark, it saves a lot of problems in the future. If you're stocking several then you're going to need several caves, usually the number of fish plus another 2-3 to allow them to "choose" their favourite. The line of site should be disrupted with plants, rocks etc, they can be fairly territorial when in their caves. Dwarfs tend to love plants, it gives them a more varied hunting/play ground to swim in, so put as many as you like in.
What ever you decide to feed them (it has to be fresh/frozen foods NOT flake, bloodworm, shrimp, brine shrimp, prawns etc) make sure its varied and that you regularly feed them live snails to crunch on to keep their ever growing beaks in check.
Dwarfs should ideally go in a species tank, there is a few other fish that will be compatible but they're definately fin nippers and have been known to decimate other tank mates. Although there have been people on here that have had dwarfs get along with other fish bear in mind that they get a lot more grumpy as they get older, considering they can live for 12 years or so thats one VERY grouchy fish
Apart from that, enjoy them, they're fantastic fish with lots of personality, you won't get bored of them
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