Hello,
I have 4 females in a 55 gallon and two 10 gallons with one male in each. The males seem to be fine in the 10 but with the water and two hides sometimes I think a 15 would be better... I just don't have the room right now. They were babies when I got then and they grew up nicely. A 10 gallon is definitely too small for two females. As for company I know most people will say they don't care but two of my females seem to chill out together often. Then hang out in the same stump and when they are out of the stump one of them usually uses the other for a pillow. Maybe they are friends. I don't know because I cant get inside their little heard but its funny those two like to be together and the other two don't seem to care. I vote for getting two geckos if you have room for a bigger tank. I always like to believe they have individual personalities. IMHO Glass is best for these Geckos because they need the heat pad under one side of the tank and it's not a good idea to do that with plastic.
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Anne
East Coast Reptile Supply
www.eastcoastreptile.com