Does anyone have one that will not do well in the top of the tank?I have had one that is in great shape,had it for about a month,and while acclimating it,cannot get it to open anywhere but on the bottom.Have read in the Sprung book that they "Prefer very strong illumination and water movement",while the Borneman book states"They adapt well to most current regimes,although they are not fond of heavy currents...Very photoadaptive and tolerate many lighting schemes"Should I leave it where it is,or try to move it up even slower?Tank is 55 gallon,440 watts PC,sea-swirl 3/4",mag 9.5 as return.Everything else is doing fine in the tank,with proper expansion,but this one has me thrown....any ideas?Thanks,Joey