5 must dos when switching from HPS to LEDs!

1. When retrofitting an environment for LEDs make sure you add in additional dehumidification to account for the lack of radiant heat given off by your HPS lights. This is imperative in order to keep your VPD in the pocket.  Use the following formula to calculate how much dehumidification is needed: [number of plants] × [gallons plants are feed per day per plant] x 8 [gallon to pint factor] = [recommended dehumidifier performance] You will also be getting a little bit of dehum from your AC so don't forget to include this amount in your calculations.

2. Along with your dehumidification you will also want to ensure your environment has proper HVAC (cooling and heating.) The more control you have over all environmental factors the better. Use the following formula to calculate how much cooling is needed. 1 watt = 3.412 BTUs. There are 12,000 BTUs/ton of refrigerant.

3. With the increased PPFD your plants will now require and increased amount of CO2. Once over 1000 PPFD, a good rule of thumb is, 1000 PPFD = 1000 PPM of C02, 1100 PPFD = 1100 PPM and so on up to 1500.

4. Get a light meter to measure the PPFD and calculate your DLI. I really like the apogee but there are other cheaper options available. A general rule of thumb is 100-300 PPFD for clones/seedlings, 400-800 for veg, 800-1200 for flower. The DLI transition from veg to flower is super important to monitor as lots of operators burn their plants during this period.

5. Monitor your fertigation strategy closely. With the increase in light energy and C02 you will also need to increase your feed. Obtaining a good EC and WC sensor will allow you to collect data about what’s happening in the root zone and adjust accordingly.

Happy Growing!