how/need to bring pH down?

[fixed]

In my 150 aggressive tank, my Pinpoint electronic pH monitor apparently has been misleading me (despite careful calibration). It has been reading 8.0-8.1, but upon double checking with both test strips and a fancier chemical test tube test, I'm getting 8.5. I had been adding buffer to bring it up, but now it's too high.
What's the best way to bring it back down? Simple pH Down additive, water change, pure top off water, or just wait it out, as that's the natural progression? Or, is this a problem at all? If it needs to come down, how quickly is best? Thanks.

 

[beth]

I really don't like the pinpoints due to erratic readings. Do water changes. That should get the job done for you.

 

[misfit]

Beth did you find that all pinpoints had arratic readings-I just bought one for calcium last night.I found the chemical calcium tests to be hard to read(tell the color)????

 

[fixed]

My Pinpoint salinity monitor just went nuts, too. Worked fine for a few weeks, not it's off by a good 20%. I like the idea of having a simple, digital, tester, but I suppose it isn't worth anything if it's off or required recalibration all the time.