Can I house 3 geckos in a 20 gallon tank?

The dimensions are:
Length: 24 in
Width: 18 in

I would house 2 females and 1 male together (none are giants)

No. That is not nearly enough space for 3 geckos. That's not even a 20 gallon long.

That's just the right size for one gecko, but 3... No. And males should NEVER be permanently housed with a female(s) as he will breed her to death (either until he dies or she dies. He won't know when to stop and could end up killing himself or killing her). Females can be housed together although I've heard of plenty of times when they just attacked each other out of the blue. You could house the two females in a 40 gallon, but you would need two of everything. Two warm hides, two cool hides, two water/food/calcium dishes, that way they don't have to fight over anything.


Sent from my iPhone using Tapatalk

The above isn't exactly true (some breeders house in male-female harems year round), but I would not recommend it. Breeding geckos isn't something to be taken lightly. It's always a risk to the health of the animals, and it's a lot of work.

Besides that, agree with everything else said above.