where do i put this one? where do i put this one?

Pen Style

Digital pH meters for hydroponic nutrient monitoring

Water Systems & Filtration

HM Digital Pro Series COM-100 Pen Style TDS/EC/Temp Meter

$74.95
Digital pH meters for hydroponic nutrient monitoring

Water Systems & Filtration

HM Digital Pro Series COM-300 Pen Style PH/TDS/Temp Meter

$159.95
Digital pH meters for hydroponic nutrient monitoring

Water Systems & Filtration

HM Digital TDS-3 Pen Style TDS/EC/Temp Meter

$19.95