Dwarf Puffers do not need any kind of special equipment for the most part. There should be a heater to keep their water around 80F and enough wattage in the hood lamp to nicely illuminate their tank (and grow your plants if you're using live ones).
The only area that you do not want to skimp on is the filter. Dwarves, just like all other puffers, are messy eaters and produce a lot of waste, therefore a good filtration system is essential. Power filters such as Hagen's Aquaclear series or Marineland's Bio-Wheel series are excellent for Dwarf Puffer tanks. If your puffers are very small, make sure to cover the filter intake with some type of foam to protect them from getting sucked into the filter.

AquaClear
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Bio-Wheel
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Filters come with various types of media which usually consists of a pad or bag full of activated carbon, and sometimes a foam block. The carbon is useful in cleaning up the water but also makes it more difficult to treat the water with medications, supplements, etc. It is advised to remove the carbon altogether and just use good maintenance habits to have clean water (it's really up to the hobbyist, though). Pufferpunk uses a stacking method on the filter media in her puffer tanks that works very well:
"As far as the stacking method: Aquaclear filters come with a foam rectangle. That goes on the bottom of the box. It is used for mechanical filtration & is rinsed every week. Next, is a 1" layer of filter floss. This "polishes" the water & leaves it crystal clear. I rinse it every week & toss it every month. On top goes a bag (I use an old fishnet stocking) of Bio-Max. This is for biological filtration & is lightly rinsed every month."