400w HPS heat question

I've been using a 175w MH and 150HPS, so Im new to higher wattages and heat issues.

I just purchased a 400w hps system and wanted to know a few things about temperature.
I have taken a few reading with the sensor at the top of the canopy and it is reading at around 90-92.
2-3 inches down it is reading at around 84-86. 8 inches down from the canopy it reads at around 76-78.
Outside room ambient temperature is 76.

Should the light be moved farther up by 3 inches so that he canopy is below 90 degrees? the plant's aren't showing any signs of heat stress.

Whats the distance between the light and the top of plants? I try to keep mine about 12 inches from the top with a fan blowing between the light and the plants, helps.

like alwaysfubar, i keep mine around 10 to 12 inches from the tops

naimad1234 said:

like alwaysfubar, i keep mine around 10 to 12 inches from the tops

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cool thanks. It's at about 8 inches from the glass right now. it is not air cooled at the moment, it's something I'm working on getting rigged up.