I always find the chameleons are EXCELLENT hiders, I put a few in my 4ft tank with threadfins, corydoras, otocinclus, Borneo suckers and Riffle shrimp. So far the only times I have actually located the chameleons is when I cause MAJOR disruption in the tank. Mainly moving all the plant life and logs and basically anything the shrimp could and would be hiding on, under or in. Once I have basically chased everyone out of hiding holes I am always pleasantly suprised to find plenty of chameleons and Riffle shrimp still all in attendance, if a little miffed about being dislodged. Even in the tank that has lots of blackmore river shrimp I can rarely locate the chameleons that I know are in there, they just prefer the hollow log and being under the leaf litter instead of being out in the open. If you do go for another tank with just chamleons then I would go at least 30-40 L, with heater, light and filteration. Plants I would say are a must as is some nicely aged timber and good old IAL. The main thing I have found with native shrimp is to do as Dave suggests and pre-age the water before doing water changes, this seems to really be the main way of ensuring the shrimps survial, thriving and breeding.