the time a gsp lives in freshwater is minimal... so for the sake of argument.. by the time it gets to you.. it should be in brackish water.. 1.012 by the time its 6 months old to 8 months old it should be marine... and for the person that stated acclimate one from fresh to salt in a bucket dripping... only if you want to cause the fish a great deal of pain and a tuff slow death.. simply top off the water with saltwater.. as in evaporation... instead of toping off with fresh to maintain your salinity use saltwater... to raise it.. as in over a weeks to a months not one night.. .02 every week or 2 is an exceptable increase and wont bother them... my gsp's are about 7 months old and been in full marine at 1.024 for about 2 to 3 months now.. get along fine with others, and live with crabs and snails and dont bother them.. but tank mates are at your own risk.. great, healthy, funny, entertaining... just my thoughts on these fish.. but by no means in any way, shape, or form freshwater... they must have some degree of salt to maintain health! good luck!