PLANTS TRANSPIRE ABOUT 99% OF THE WATER THEY RECEIVE, SO THE AMOUNT OF WATER YOUR PLANTS RECEIVE IS APPROXIMATELY THE AMOUNT THAT NEEDS TO BE REMOVED EACH DAY.”
Conduct this experiment during a time when moisture is most problematic, such as when plants are large and the external environment is humid. Don’t forget that air conditioners often don’t run continuously when the lights are off. In other words, if the air conditioner runs constantly when the lights are on, but only for, say, 30 minutes when the lights turn off, your air conditioner isn’t removing any water for a major portion of the cycle.
How Much Moisture Needs to be Removed to Protect My Plants? Plants transpire about 99% of the water they receive, so the amount of water your plants receive is approximately the amount that needs to be removed each day. For example, 30 plants each receiving 1.89 L per day is 56.78 L total water per day. If you water every other day, divide by two to get an average per day. Use the results of your moisture collection experiment to subtract whatever water your air conditioner removes from your total input water. If you have a remainder then that is the water that must be removed by a dehumidifier. It just so happens that dehumidifiers are sized by their capacity in pints per day. It is important to check these numbers at the peak of the plants’ growth or the final two weeks of flowering. A little understanding and a little investigation coupled with a bit of math is all you need to ensure you have the right equipment to protect and grow your investment under all circumstances. If this humidity 101 lesson still leaves you with unanswered questions, the experts at your local hydro shop should be able to help, or try submitting a question to Maximum Yield experts by going to maximumyield.com/features/asktheexperts
Maximum Yield | March/April 2014
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