I would seperate them antil you can sex them. The different size of them can be an indicator that they are both males and one is more dominant then the other.
Day Geckos need more UV-B. I don´t know if you can buy better lammps in SA. Her in Europe we use Spots like Solar Raptor ore Bright Sun. Maybe you can buy somethng like this: http://www.reptileuv.com/megaray-sb-100-watt-self-ballasted-flood-uvb-lamp.php Your Gecko need Calcium for the cetral nervous...
Wich kind of Gecko is it and which lamp do you use or UVB? I hav seen that most uf you use Compact-Lamps This is not enough. Here you would be "killed" for just using only this as UV-source.
I built this paludarium for Shinisaurus cocodilurus. But I have to put a much of money aside fo them. A pair costs five times as much money as I earn in one month of hard work.
And that the reason for beeing inaktiv in the forum for long time: http://www.sareptiles.co.za/gallery/albums/userpics/23442/IMG_8242.JPG http://www.sareptiles.co.za/gallery/albums/userpics/23442/IMG_8247.JPG http://www.sareptiles.co.za/gallery/albums/userpics/23442/IMG_8251.JPG