Grow Mediums Two calibrated pH pens, two different readings

[Simplicio]

Cheap pH pens have unreliable, short lifetimes.
Always have pH strips or fluid on hand in case the pen craps out, or reads unreliably.
I like my apera model, and it takes my horrible abuse very well.

I sometimes accidentally leave it uncapped overnight, but it keeps chugging along.
Mine never gets stored in the storage solution.
The reservoir drips that automatically accumulate in the cap work fine for me.

 

[Olderfart]

Cheap pH pens have unreliable, short lifetimes.
Always have pH strips or fluid on hand in case the pen craps out, or reads unreliably.
I like my apera model, and it takes my horrible abuse very well.

I sometimes accidentally leave it uncapped overnight, but it keeps chugging along.
Mine never gets stored in the storage solution.
The reservoir drips that automatically accumulate in the cap work fine for me.

My Apera is young, and I ran out of the minuscule amount of storage solution that came with the kit, so for the last few weeks it has been stored with the cap on with droplets of tested solution in there to keep things from getting dry.

However, I ordered some KCL, and will, likely later today, put together a 3M solution of KCL, after which storage will be in that solution.