Salinity measurement

[workfortheman]

Anyone have a good way of converting something like specific gravity to cups of salt per gallon or something? Reason I am asking is that I am planning on gradually shifting my tank to brackish water, and want to be able to calculate how much salt to add per week or whatever. The salt I'm gonna be using is Instant Ocean. Thanks in advance!

 

[workfortheman]

OR,
should I just get a hydrometer (which I was gonna do anyways) and trust that it is accurate at this low SG?

 

[Pufferpunk]

You absolutely need to use a hydrometer. Instant Ocean makes one that starts at 1.000. Just for an estimate, it takes about a cup of salt/5gal to raise the SG .005. You can only raise it .002/week as to not kill off the FW bacteria in your tank too quickly, before the SW bacteria can develop. What kind of BW fish are you keeping?

 

[workfortheman]

GSP's they will probably only spend a year or less in this tank, so i figure I will shoot for 1.005 in that time frame. Likely my next tank will be heavily brackish.
Thx for reply