OK, its a hot tub question, but with the pool closed for the winter its the only outdoor water I can have fun in. I have a 6 person soft tub that has the following readings.

Bromine 6
PH (ranges from 7.0-7.9 from week to week, most of the time its low and i have to raise it)
Alk - 200

I currently use a bromine floater and use that all in one shock every week that says it has a ph lock/alk balancer blah blah blah. I also use Ph+ and Ph- (the cheap powder stuff from home depot) to balance the Ph.

My question is. My ph values seem to be up and down every week, is this because of the high alk? The manual says to replace 100% of the water every 3 months, so with a change of water due for me in another month do I worry about the alk if I constantly adjust the Ph? or should I really be concerned with bringing the alk down... and the second question is how do I bring it down in a hot tub? is it the same deal, lower the Ph to 6.8 and then aerate till the Ph rises to 7.6. We currently only use the hot tub once per week so its not getting used a whole ton.

thanks in advance