Tank upgrade, can I use new salt?

[Orito]

I'm going to upgrade my 100 liters AIO to a 250 liters with sump, my biggest doubt is about the new water.
I'm planning to use most of the possible old water and complete with fresh made saltwater, in the current tank I use IO purple, but my parameters aren't close to fresh IO water, my kh is around 7dkh and fresh IO is around 10, I'm thinking about getting a salt mix with closer dkh, aquaforest, fauna marin or red sea blue bucket.
Do you guys think is a good idea?
I still have plenty IO that I could use.

 

[Ron Reefman]

Is the alk the only issue?

To be honest, a jump of 3.0dKH is kind of big. But your mix will be closer to 8.5 dKH or a bit higher. I've bumped alk by more than 1.0dKH and my sps corals were only a bit ticked off for 5 or 10 minutes and then all came back out.

I wouldn't worry about it.

 

[Orito]

Is the alk the only issue?

To be honest, a jump of 3.0dKH is kind of big. But your mix will be closer to 8.5 dKH or a bit higher. I've bumped alk by more than 1.0dKH and my sps corals were only a bit ticked off for 5 or 10 minutes and then all came back out.

I wouldn't worry about it.

one option I have would be lower the alk with sodium bissulfate that I already have, but then I think my ph will drop a lot and I don't know if will have enough time to let it rise back

 

[ScottJ]

Could you do a couple large water changes a couple days before the move? That might get the old water closer to the new water.