well i filled my tank up today with 55 gallons of RO water from the local fish store. I then added about 7 lbs of sea salt, i forget the brand. It was about half a bag that came with the tank. Im not sure how old it was. Anyway, the majority of the salt dissolved within 10-20 minutes. I let 2 powerheads run in the tank to get some flow and mix it up quicker. but theres still a considerable amount of salt particles that just settle to the bottom and float around when i try to stir em in. Theyve been there for hours and show no signs of dissolving? I know i need to get more salt tomorrow, the hygrometer doesnt evenregister the salinity yet. but what to do about this undissolved salt? think the salt was too old?