I just added 2 gallons of rodi and put one gallon on a slow drip tommorrow ima do a 20 gallon water change
after about 30 minutes ill see what the new number is. As to the calibration we did it about a month or so ago with someone who knew how to calibrate it i myself dont know how.
So i been using a cheapy one cuz its easier and i noticed today it was broken so took out my refractometer and my Salinatiy is 1.032 ouch how much top off water do i need and how quickly or slowly can i lower it going to run out to buy some wondering how much ima need.
So when i moved my tank we used the same sand and some members said this is a very bad idea. Cant remember the ins and outs but are you going to use the same sand?