Rookie Cymbidium Owner needs knowledge from veterans!

[orchids3]

You can invest in an expensive meter or buy a pH test kit from a hydroponics store. The kit costs around $3. When you are ready to test pH put your plant in a pan and water it, catching all the water that runs thru and leave the pot in the pan for and hour or more. Take the pot out and measure the pH of the water. That will give a pretty good indication of what the roots of the plants are experiencing. As potting media decays it drops the pH - thats a good case for repotting when the media begins to decay. The pH check gives a good indication of media condition as well as telling you what the pH of the fertilizer solution. Too many, cymbidiums are good Semi Hydroponic candidates. Having just been "sold" on the idea I wont comment too much but it does seem to be working well. I pour off some of the fluid from the resevoir in the bottom of the pot and check that for pH.
The best thing I have found to adjust the pH level with is Dolomite Lime. I put 1 tbl spoon per gallon pot twice a year as a top dressing. The pH does not drop. My media is differant than yours but the fir bark is ok. In addition to buffering pH, Dolomite lime adds a good source of calcium and magnesium -essential to cymbidium health. The Calcium levels in cymbidiums is almost twice what you will find in any other orchid I know of. Give the cymbidiums planty - in addition to the Dolomite lime I add gypsum to the mix when and crushed oyster shells.