PH pens and Nutrient meters are probably the biggest single hassle for indoor gardeners but if you understand them then it gets a lot easer.
PH pens are a tool for measuring the PH of your water, nutrient solution, or runoff and if used and maintained properly they can have a good long life, if they are mistreated then they will cause you nothing but grief.
A PH meter either hand held or wall mounted, use a permeable glass membrane probe inside this probe is a liquid and some wiring. Now if this probe gets clogged with crud or is allowed to dry out the pen will either stop working properly or die completely.
Both of these problems are quite easy to remedy with a little care thus increasing the life of your fairly expensive PH tool.
Storage of your PH Pen is very important as it will greatly extend the pens life, whenever you are not using your PH pen it should be stored in a “storage solution” this keeps the pens permeable membrane glass probe moist and does not allow it to dry out.
A #4 PH calibration solution works very well as a Storage Solution and is very inexpensive.
It is a good Idea to clean your PH Pen every now an then this will help to make sure you are receiving accurate readings and again extend the pens life, there are PH Probe cleaning solutions available at garden centres. Most consist of a two part system with an A solution and a B solution follow the directions on the bottle but it generally consists of 5min in A then 5min in B then 5min in A again.
Some pens have specific maintenance needs one in Particular is the Hanna Champ this PH Pen has a small cloth like strip next to the PH probe itself.
This cloth like strip is held in place by a rubber plug every once in awhile it is necessary to pull a few millimeters of this material out and trim off the dirty old portion. making sure to push the rubber plug back into place afterwards.
Never Ever store your PH Tool in Distilled water this is probably one of the fastest ways to make your PH Pen a high tech paper weight.
My Personal Preference is to use a continuous read out PH meter, these simply mount on the wall and give a constant 24 hour a day read out. The probe is constantly in the reservoir so the probe rarely dries out, also the shear size of the probe gives it a much longer lifespan.
Unlike other PH Tools these don’t necessarily need to be calibrated every time you use them as they are always in the reservoir, it is however a good idea but I have seen them go months with little to no drift.
The initial investment is a little more but the hassle factor and ease of use makes them well worth it.