ph levels at 8.8?

[digitalsteve]

hey guys, my ph seems to have leveled out at 8.7-8.8, and every time i add new weater it still goes back up till it plateaus out at this mark, is there anything i can do to drop it or get it to stablize at a lower ph? the tank has been up for about 7 weeks now and all my other params are where they should be, ammonia-0 , nitrates-0 , nitries-0, and sg 1.025