Adjusting wattage during the day

GreenForMiles

GreenForMiles

Active Member
Hello, in my flowering room I have a 1,000 watt hps. It’s in a ventilated hood and keeps the room about 77-80 degrees IF dimmed to 600watt. When I run it at the full 1,000 it can climb up to 90 degrees F(100 directly below light) in just a few hours.

I was thinking one solution to getting maximum lighting would be to run it at 1000watts for 2 hours, then switch to 600watt until it cools again. Perhaps I could also just introduce the 1,000 watts a few hours a day around noon.

my main concern is what affect will changing the dimming have on my plants? Is it going to stress them out, Or will it just be like the sun is rising/setting? My lights already turn off 15minutes every 2 hours to control heat. Any insight would be greatly appreciated, tia!
 
B

Ben123456733

Well-Known Member
Like Rurumo said, run them overnight into the morning, at the coolest hours.
Also if you don't already have one, get an oscillating fan blowing on the upper part of your plants. Simply doing that could reduce the heat on your plants tops by 5-10 degrees.
The last 2 options would be to either get an AC unit or look into switching over to LED. Neither one of those is going to be cheap but they will have the most dramatic effect out of anything you could do.
 
VincenzioVonHook

VincenzioVonHook

Well-Known Member
Ben123456733 said:
Like Rurumo said, run them overnight into the morning, at the coolest hours.
Also if you don't already have one, get an oscillating fan blowing on the upper part of your plants. Simply doing that could reduce the heat on your plants tops by 5-10 degrees.
The last 2 options would be to either get an AC unit or look into switching over to LED. Neither one of those is going to be cheap but they will have the most dramatic effect out of anything you could do.
Click to expand...
There are really good leds going around dirt cheap these days. My housemate had a 1000w hps setup for two years. It was putting out around 1100 ppfd at 24" in the hotspot, but was an ass to cool and cost alot to run. He switched to a Mars Hydro LED, and at 18" it pulls the same ppfd at one fifth of the power and heat, and less outright cost to purchase. I'm not sure what model it is, but it pulls 300w from the wall, costs around $250 and ended up with more uniform coverage.

I have a feeling it was the TSW 2000 if I remember correctly.
 
ZenWolf

ZenWolf

Well-Known Member
GreenForMiles said:
my main concern is what affect will changing the dimming have on my plants? Is it going to stress them out, Or will it just be like the sun is rising/setting? My lights already turn off 15minutes every 2 hours to control heat. Any insight would be greatly appreciated, tia!
Click to expand...
Personally I think I'd go more with dimming to control the heat vs turning the lights off and on totally. That said, I doubt doing either or both causes any real stress during vegetative growth (different story if we're talking about interrupting darkness during flowering with light). Outdoors, sun exposure varies tremendously throughout a day due to clouds, fog, storms, etc and plants deal with it fine.
 
raggyb

raggyb

Well-Known Member
GreenForMiles said:
Hello, in my flowering room I have a 1,000 watt hps. It’s in a ventilated hood and keeps the room about 77-80 degrees IF dimmed to 600watt. When I run it at the full 1,000 it can climb up to 90 degrees F(100 directly below light) in just a few hours.

I was thinking one solution to getting maximum lighting would be to run it at 1000watts for 2 hours, then switch to 600watt until it cools again. Perhaps I could also just introduce the 1,000 watts a few hours a day around noon.

my main concern is what affect will changing the dimming have on my plants? Is it going to stress them out, Or will it just be like the sun is rising/setting? My lights already turn off 15minutes every 2 hours to control heat. Any insight would be greatly appreciated, tia!
Click to expand...
@GreenForMiles, I'm wondering if you have continued to vary the wattage throughout the day and how has it been working? I'm thinking of doing the same.
 
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