you really don't need to be concerned with your mediums ph. unless your plants are displaying some issues, all is good. in soil, you're likely to see a ph that seems to be out of whack with what is suggested, 6.5. if you water/feed, and allow for a little run-off, this will help flush accumulated nutes. some folks do a feed, feed, flush routine in soil.
Get this kit. You can order it anywhere online..Amazon is just easier or you can get it at a pet store. They sell them for aquariums. Comes with a PH Up, Down, and tester kit. Its a idiot proof kit. [ame=http://www.amazon.com/General-Hydroponics-pH-Control-Kit/dp/B000BNKWZY/ref=sr_1_1?ie=UTF8&qid=1305443159&sr=8-1]Amazon.com: General Hydroponics pH Control Kit - PC500: Patio, Lawn & Garden[/ame] Make sure you PH Balance the water after nutes are in it.
Dolomite lime won't necessarily bring the pH in the direction he needs it. You can get Ph Up or Ph Down at a pet store in the aquarium section.
For soil? I swear dolomite is neutral and will bring anything acidic back to neutral. Please correct me Toasty because I am probably wrong, still relatively new to organics.
Yes dolomite is neutral. But if your pH is 8.0 and you are trying to get to around 6.6 then adding something that's 7.0 will help but won't do the job. If you're at 6.8 and add dolomite you will be going very slightly in the wrong direction. It's definitely useful for managing pH but it isn't a simple plug-and-play solution to the problem.
Lol I reread the OP and you right, dolomite will "change the pH" but only closer to neutral. Where in his case he could need to change it in any direction. Live and learn. This is why I like GC.