I might suggest that you try and work your sump or water change vessel so that you can put in a whole bag of salt, if you are a bag user. If you use the whole bag, the parameters will be on the money whereas if you just use some of it, the contents might have settled or separated and you can have inconsistent results unless you mix the sale before use. With IO, this is 44G for 1 bag, or 88G for 2 bags at 1.026 IIRC.