Equipment Every Greenhouse Should Have

by John Erwin

Professor, Department of Horticultural Science

University of Minnesota

How many times would you like to know your pH and EC immediately to decide what to fertilize with at that moment? What is your plant temperature? Is your media temperature what you think it is? Do you have a virus in your crop? Are your lights positioned to give you the amount of light you need for night break lighting or supplemental lighting? What temperatures did your plants get exposed to during shipping? New instruments available on today can answer these questions.

pH Meters

pH impacts whether nutrients in the media are available for plant growth or are tied up in the media. Many of the crops we grow today have very specific pH requirements. If pH levels drift out of the optimal range, plant growth is reduced and nutrient toxicity and/or deficiencies will occur.

Additional reference material can be found at:

http://en.wikipedia.org/wiki/PH_meter

Where to Get One?

A list of sources for a variety of pH meters is shown below. A couple of points: 1) I have found that the surface sensor monitors can break easily, and 2) the best meters are still the lab grade meters that sit on a bench and you bring the sample to them.

Sources:

Cole-Parmer

http://www.coleparmer.com/catalog/product_index.asp?cls=3415

Hanna Instruments:

http://hannainst.com/usa/subcat.cfm?id=002

Myron Instruments:

http://www.myronl.com/products/ds_pds.htm

Omega:

http://www.omega.com/toc_asp/sectionSC.asp?section=BB&book=green

Spectrum Technologies:

http://www.specmeters.com/pH_Meters/