I am from the UK and have no idea what gallons are for a tank size. I only know how to work in feet. I have a female bosc (shes about 2 feet top to tail) and she is in a 4x2x2 (lengthxwidthxheight) 2 leopard geckos in 1n1/2x2x2 and a blue tongue skink in a 4x2x2 are these size ok for them all???