[Myka]

Like I said, I would aim for about a week in your case or 0.001 per day if you find that easier to figure out. If salinity was low for longer you would have to take more time to raise it. Since the salinity hasn't been low for very long, you can raise it a bit faster.

Do you have an ATO? Personally, I would make the top up water super salty instead of fresh water. That would probably be the ideal way. Otherwise, I would just add 2 cups of salt to the sump at a time several times a day. That shouldn't change it very quickly on a tank your size. If all else fails you could remove 5 gallons of tank water, add about 10 cups of salt and pour it back into the sump, but that will make the salinity increase in jumps. Whichever way you choose to raise salinity, figure out how much that changes it on each "dose" (or each hour with the ATO) to make sure it isn't going up too fast, recheck at the end of the day. If you're using a hydrometer, make sure it is calibrated with a refractometer. If you don't have a refractometer maybe Doug (fishytime) can calibrate the hydrometer for you while you're picking up salt at the store.

Doing changes with high salinity water like SG 1.030 would waste a lot of water and a lot of salt (throwing out the water you remove), not to mention take you about 5 years to get the salinity up.

My guess is your Hippo Tang will have an Ich outbreak after this. Dang Hippos...