Best distance between

Hello Everyone, I have just purchased my first Grow Light ( Mars LED 450w ) and will be using it for raising seedling ( Desert Roses and indoor type seedlings ) so for what I have read so far I need 24” ( 60cm ) between the seedlings and bottom of the Mars Light. Is this correct? Thanks in Advance

It's in the ball park Personally I prefer taking the guess work out of it and use a PAR meter. Why[FONT=Arial, Helvetica, sans-serif]?[/FONT]

• cutting/seedlings 60-90 umol;
• clones 100-200 umol;
• veg 300-425 umol; and
• flower 700-1200 umol

Many don't use one and opt for the heat on the back of the hand at canopy level. If you can leave your hand there for 5 sec, you are golden. Junk science if you ask me (my humble opinion)

Many will say I am not spending that kind of money for a meter. You can get a meter for less than the cost of an oz. It pays for itself the 1st run. Once again IMHO.

If your light is to close you'll burn your girls and if it is too far, your plants will search to reach the light and become leggy. Let's just say I am glad I acquired one. Not only that... it permits me to strategically position my girls to receive maximum/uniform exposure (as close as I can get it), as the light footprint is not the same value throughout your spread. https://www.youtube.com/channel/UCSZwj4zGhH1yklVFxS54qdA Although his channel does reviews on various lights, he always compares them against his products. That being said... the steps he goes through are sound and, you will see the variance in the footprint between readings.

I am not sure if I would grow Adeniums in there as they have different climate requirements. If you are setting your tent up for cannabis, then dial it in for cannabis, without reference to how your desert rose is doing. Who knows they might actually thrive But IMHO it is a companion plant at the end of the day and we are trying to maximize cannabis production.

Thank you Switcher56, I didn’t realise how exact the distance needed to be. The Par Meter would be the best method just the cost of these make it an overkill when I’m not growing Cannabis ( illegal in Australia ) I looked at the YouTube link you gave me and found the one on methods of determining the height.

I think the infared thermometer technique by taking the temperature of the plant leaves and matching it with the room temperature sounds perfect for me as I have different heights to allow for since I have both Seedling as well as wanting to add a few plant cuttings. So I will need to raise the seedling trays based on the tallest plant rather then everything sitting on the same level as I have at the moment ( see attached image )

The setup is for my Wife for her Gardening hobby as most of the time when she grows things by seed the seedlings either die from too much light/sun or go all “Leggy” from a lack of light and fall over and die. Hoping to get her hobby more advanced and successful

Sounds good to me

Recommended Hanging Distance Above Plants: Seedling stage: 20''~28‘’ Veg Stage: 16''~20‘’ Flowering Stage: 10''~16‘’