1000 watt hps canoeing problem

New 1000watt hps is dimmed to 600 watts but still have leaves canoeing if I drop below 30 inches. Why is this?

MH/HPS generates a lot of heat and radiant heat is causing leaf surface temp to be too high for the plant. Turn down further or mover further away.

Yeah but there’s no heat between plants and light. Its air cooled with glass cover. It’s a 4x4 tent. Just to much light saturation is all I can thik

Have 6" infinity fan running directly off it. My temps in tent only 75°f at max

Has no bearing on air temp. Look up radiant heat.


I just dont want to starve plants of needed light. Thanks for response, much appreciate it!! I’m fairly new to this but trying to make best of it lol. I’ll look up radiant heat and see what I can learn

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Ok so looked it up, radiant heat is the whole hand test. But that’s why I’m stumped. It’s cool between light and plants. I’m total noob so don’t get frustrated lol. Never had this problem with 600 hps but 1000 is all new to me and I have it dimmed to 600. There is like no heat between light and plants

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Nvm I read further. I see the situation but dam lol. Ill leave at 30 for now see what happens lol

The easiest thing with MH/HPS is to let the plant tell you what it likes. If it’s praying and canoeing then raise light/lower output until the plant relaxes. Also; a lot of growers hammer their plants 24/0 with high intensity light; after the plant reaches it’s peak DLI (Daily Light Integral) it cannot accept more light and make use of it so can go into ‘pray’ mode. Plant is just protecting itself.

And there are no silly questions.


How often are you watering , HPS you will water more often due to dry heat and if you don’t have adequate space , they are notorious on humidity! I know it’s great power :battery:, but it takes space and good air control to run granders in a small space or tent :tent: even if the hood is being air cooled , the lights are stationary or on light movers could also be the culprit?

Is this a double ended HPS? I’ve had a hard time getting my 1000w DE HPS under control. It puts out a TON of light.

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Sorry for response delay. It’s a hydro setup.

That’s a pic of area. It’s currently on a 600 ballast with 600 bulb and still burning them. Didn’t have this problem with simple wing deflector.

Unless the yellowing is a different problem all and all

I gotta say im not seeing yellowing it all looks uniformly green to me

@Monster420 you are going to need more stretching space and that hood will put out some heat :fire:, you need a lot of air movement and air-conditioner to go in there to help hear due to not enough ceiling space for vertical growth. A swamp cooler or a stand up unit to help heat .

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Well, was going to scrog them, just havnt netted yet.

Ran into a root rot issue which slowed everything down.
Be dropping net on them tonight hopefully

Here’s a better pic of discoloration I was talking about. What’s your opinion. Light is almost 30" away and is only 600 watt hps. I’ve flushed thinking it was burn. I upped nutes after that when flush didn’t help thinking maybe deficiency. I’m at a loss of ideas lol. Never had these problems.