I just started my tank. I have no livestock at the moment. I ordered 75 lbs of uncured live rock as the salty friend advised me that this would be best in the long run. When I got the rock I placed them in tubs with dechlorinated saltwater. Later that week I got some RO/DI water from a new salty friend. I mixed the salt in buckets and let it set for several days. After pouring the water in my tank I noticed that undissolved salt was in the bottom of the bucket, it is very cold here, high of 14F today. Is there a formula I can use to calculate the amount of salt to add to the tank? I just check my salinity using a coralife hydrometer. I know plastic is not the most desirable instrument for this job but I want to spread the cost of setup as thinly as posible