alk vs salinity?

[Aquattro]

Salt manufacturers recommend crap all over the map. The water on reefs is 1.026 which is why we use that value. I still don't quite grasp why you're insisting in using less? If you have to maintain everything else via dosing, what is the value?

[146clark]

There is no value just curiousity. I appreciate everyone's comments

[Aquattro]

Well, for curiosity's sake, I suppose you probably could keep a reef at 1.023. I'm sure there are enough refractometers out there that are out that much I ran a reef at 1.031 for almost a year, nothing died lol

[146clark]

The reason for using it at lower salinity is because right now with the salt I use I get the dkh level I want. If mixed to 1.026 it's at a value I don't want.

[Aquattro]

Well, as Denny explained, I wouldn't use salinity as a means to control alk. Use a different salt if it's that important. RBS is low, and other than costing more, nothing wrong with it. You don't NEED alk to be low just to run zeo, running it a bit higher is fine.
But, your whole tank will be at whatever level you set the alk. Say 7. If you then do a 20% water change with IO at 8.5, the net result will be pretty darn close to 7 and will balance out quickly with the system.

But, you do seem insistent on running low salt, so given that, I don't think anything terrible will happen. Just not something I would personally do.