I have two BTA clones out in the greenhouse sump attached to rubble, ~3" One is spoken for if I ever get it to Nashville, but one is available. The A. akindynos up top go into them fine, so I'm pretty sure the clark's would too. If you feed them (I don't), they will grow fairly large. Seased has one of these clones for his clown pair (it grew a LOT...and it split recently too I think). They are kind of pinkish colored and have long tentacles under sunlight, but I brought one inside last month for my A. bicinctus pair, and it bubbled up and looks to have more green in it now, although I'm still waiting for the clowns to find it.