How big should the tank be?
Would a four gallon be enough to house two or just possibly one?

African Clawed Frog Questions - Please Help
There is some good information in that topic about the care of dwarf frogs... Hope it helps

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i believe a 4 gallon would be fine for the dwarf variety, they don't get big at all.

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My name is Liz
Do what's best for the animal, not what's best for you.

How many gallons would a 9litre tank be and would that be good for two of them?

Please anyone!

I'm going to assume you mean in imperial in which case i think 9 litres is about a 2 Gallon tnk. not sure if thats okay for a pair though, youd have to ask around, personally i think the more space the better though.

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"Nobody can do Everything, but Everybody can do Something."

What about this type of tank?
18L Complete coldwater fish tank kit - Tesco.Direct

From what i've read on African Dwarf Frogs, that seems like it would house them decently, 18 liters would be about 4 gallons, but were i you, if you have the space i'd go with a 5 or 10 gallon glass tank. I think if you keep up with water changes dwarf frogs actualy do better without a filter, if it gets rather cold where they will be id suggest a aquarium heater though, id check caresheets for them for the right temps, other then that you want a good fitting lid, they may try to escape, and can dry out very fast away from water. Also, i would use river rock instead of gravel, you dont want them accidently ingesting any of the substrate. I think you'll have more luck setting up a 5 or 10 gallon tank for them then buying a kit.

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"Nobody can do Everything, but Everybody can do Something."

Hmmm I know a bigger tank is always better but as some of you may know "The money problem"
So far I can afford this tank and have read that you could keep around 2 in a 1 1/2 gallon tank.
Buy Cold Water Fish Starter Kit at Argos.co.uk - Your Online Shop for Pet accessories.

I understand "the money problem" and i'm not positive about the difference in price, because of the different currencies, but i beleive 9.99 in GBP, is almost 20 dollars american, you may be able to find a used tank and lid for less, new they 'd probaly run about 25 dollars american.

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"Nobody can do Everything, but Everybody can do Something."