JWM2
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This is easy. Your rate of transpiration changed with the new light. LEDs put off less ambient and infrared heat thus lowering your leaf and ambient temps. This causes the plant to transpire less and therefore the nutrients remain locked in the growing medium inaccessible to the plants roots.
This is a common issue when switching over and takes some adjustment to get right. It’s easy to over compensate and create a situation where the environment becomes too dry and you’ll see a wild swing from not enough nutrients to nute burn.
This is where a VPD monitor comes in handy. You may notice that you’ll need more humidity for the plants to be happy otherwise you’ll need to cut back feeding in order to compensate. The easiest thing to do is to get the right humidity for the plant to be comfortable and not make other unnecessary adjustments to compensate.
It really comes down to providing them an ideal environment and since your source of light changed the environment changed drastically as well. With LEDs you want higher ambient room temp which raises the leaf surface temp and higher humidity which will keep transpiration in check. Once these are fixed you’ll notice that your plants will grow as expected again.
I run at 80-85 degrees ambient with about 60% humidity. This puts my VPD in the 1.4-1.6 range in flowering. In veg I like a lower VPD which requires either lowering the ambient temp or raising the relative humidity. In veg I shoot for 1.1-1.4 kpd.
This is a common issue when switching over and takes some adjustment to get right. It’s easy to over compensate and create a situation where the environment becomes too dry and you’ll see a wild swing from not enough nutrients to nute burn.
This is where a VPD monitor comes in handy. You may notice that you’ll need more humidity for the plants to be happy otherwise you’ll need to cut back feeding in order to compensate. The easiest thing to do is to get the right humidity for the plant to be comfortable and not make other unnecessary adjustments to compensate.
It really comes down to providing them an ideal environment and since your source of light changed the environment changed drastically as well. With LEDs you want higher ambient room temp which raises the leaf surface temp and higher humidity which will keep transpiration in check. Once these are fixed you’ll notice that your plants will grow as expected again.
I run at 80-85 degrees ambient with about 60% humidity. This puts my VPD in the 1.4-1.6 range in flowering. In veg I like a lower VPD which requires either lowering the ambient temp or raising the relative humidity. In veg I shoot for 1.1-1.4 kpd.