Improper maintenance of the air pressure between the layers of double poly covered greenhouses can be responsible for premature wearing of the

film and shortened life expectancy. Here are some tips for keeping your poly inflated properly.

1. Control the pressure using the rheostat (variable speed control) that the inflation fan would be plugged into. Slowing down the speed of the

fan inflates to a lower pressure while speeding up the fan inflates to a higher pressure. Monitor the pressure with an inexpensive manometer.

2. Use outside air to inflate the poly. Outside air is usually drier and does not contain pesticides or other volatile chemicals that can interact with the poly.

3. Change inflation pressure according to the weather. Optimal inflation pressure is 0.2" of water column pressure during hot weather and 0.45" of water column pressure during cold and/or windy weather.

4. Avoid stressing the poly. If overinflated, the poly stretches and becomes thinner, making it weaker. If underinflated, the poly flaps and wears prematurely.

5. Maintain the installation as air tight as possible. Check poly locks occasionally to find and repair air leaks that lead to underinflation.