PurGro GroBot pH Probe, Industrial Replacement rock-bottom Solid state electronic ignition module—no

Solid state electronic ignition module—no pilot light necessary

organic coir cube expands up to 7 times in volume when hydrated

No bugs or pathogens

Models 101 / 102 / 103 are single-tube units that can be installed in ductwork utilizing the pre-drilled flange and factory applied gasket

Canadian Sphagnum peat moss (65-75 % / volume)

PurGro GroBot pH Probe, Industrial Replacement rock-bottom Solid state electronic ignition module—noThese don't look like the ones from the hydro store because they are double junction, flat surface pH probes typically used in chemical plants for process control. They last longer, stay cleaner and are built to mount in line inside your GroBot Evolution. Cost a few bucks more, but these are the good ones. Proudly made in the USA.