Do I need to adjust my Specific Gravity?

[jassz]

It is 135 gallon tank with a 40 gallon sump. Midweek I changed out 15 gallons (nitrate was a bit high), and tonight I changed out 10 (slight ammonia). I mixed the extra salt in to the water going in, and then put it into the sump (and also via bucket right into the tank). Tomorrow I think I'll just add as much water as it takes to dissolve several cups of salt. I figure the higher the SG, the less salt it takes to bring it up 0.001. Do you agree?