Bluelab® pH 4.0 Calibration Solution Dehumidifier Uni-Slab has the benefits of

Uni-Slab has the benefits of a slab with the versatility of a block

Added phosphorous will also aid with photosynthesis and the plant’s ability to uptake nutrients

Constructed using 1/8 in ABS plastic

produce teeny weeny harvests

Bluelab® pH 4.0 Calibration Solution Dehumidifier Uni-Slab has the benefits ofBluelab pH 4. 0 Calibration Solution "pH measuring equipment must be cleaned and calibrated regularly to ensure they are giving the user accurate readings. pH instruments are calibrated to pH 7. 0 first (buffer) then to pH 4. 0 (slope). Calibration Solution should be stored in a cool place out of direct sun and heat. They should be stored with the lids securely tightened."