lol an ADF does not need 5 gallons each. You can keep 6 in that 10 gallon tank without a problem. Be sure to use a nice, low flow filter (air powered sponge and box filters work perfect), provide lots of decoration and hiding spots in the tank to simulate a natural environment, choose a fine type gravel or sand, not big gravel or pebbles. Feed foods like bloodworms and brineshrimp, or a soft pellet meant for them.