Cool. There are a lot of smart posters and useful information on this board. My water is probably not very hard so the initial fill probably didn't add a lot of magnesium so I don't see the specs that you do. It's nice to know they aren't a problem.

As for you pH rise, you can not only lower your TA to 90, but you can also add 50 ppm Borates as discussed in this thread. The combination of lower TA and having Borates seems to really do the trick. The lower TA means the pool is less carbonated so outgasses less carbon dioxide while the Borates are an additional pH buffer and are also an algaecide that lets you cut down your SWG production (since less chlorine gets used up killing algae) which lowers the hydrogen gas bubble aeration which lowers carbon dioxide outgassing. The pH rise is mostly due to carbon dioxide outgassing.

Richard