Changing salt (Instant Ocean to Reef Crystals) - best practices?

[ConsummatePro]

I normally do infrequent 25% water changes in my 165 gal system which I changed from FOWLR to mixed reef about 6 months ago. Now doing 2 part dosing (Trident controlled), and my parameters as of this moment are alk 9.02, Ca 460, Mg 1407, pH 8.04-8.2, salinity 34.5-35. I’m trying to move to more SPS so thought maybe a salt change might be nice too.

I’ve been using IO forever but recently picked up some Reef Crystals since I found a great price. I realize these salts are likely quite similar but any advice on the best way to transition? Can I just mix up the Reef Crystals and do a usual 25% change or should I do a series of smaller changes?

What about more vastly different changeovers like changing IO to Tropic Marin, or Red Sea blue or Pro?

 

[gbroadbridge]

I would just do 10% water changes to your normal schedule.
25% maybe too much if the chemistry is markedly different.

 

[Kedron1977]

I'm no pro at this but the reason you would do a couple smaller changes before a big one is because of a possible parameter swing that could be to large.