40w CFL Bulb Temp vs. 70w HPS Bulb Temp

So over the last few days I have been doing a little experiment with bulb temps.

heres the lowdown, I used a

70watt HPS light - this light i purchased at lowes. Its an outdoor securtity lamp. I removed the lamp, bulb and ballast from its case.

I removed the photocell from the power system. I also re-wired the lamp to ballast so I could make it remote. (THIS IS KEY)

next up is a 40watt 2700k cfl. this bulb like every other cfl on the market has a built in ballast. this means most of radiant heat from comes right from the bulb area.

On too the grow.

I have the 70w hps hanging 1.5 inches from the top of a papaya plant, which is about 7 inches tall

I have the 40w cfl hanging 1.5 inches over a blue dot plant. this plant is about 8 inches tall. 5 days younger than the papaya

both plants are in 2 gallon pots with the top brimm or ring cut off. pots are nestled right next to each other, have a 10" fan circulating about 15 inches away from the plants.

i have been recording the temps once an hour threwout the light cycle. i have a little hygrometer soil level in both pots. heres the kicker, you ready for this.

avg temp of the cfl = 86f

avg temp of the hps = 79f

these temps were recorded over a three day period. each day was just like the last day. ambient temps threwout the days were equal. kinda hard to believe for this area of new england.

so in conclusion a low watt hps with a remote ballast will produce less heat than a cfl. while tripling the lumen per watt ratio!

so this means i am getting rid of all of my cfls and will be customizing my little grow box to handle more hps systems along with side supplemental lighting to help offset the small size of the grow box.

nice work, ive been thinking that my grow box would stay cooler with a 150wHPS with a remote ballast than with the 240watts of CFL's i currently have. Unfortunately, I'm not much of an electrician, and can't find one out of the box at a reasonable price.

donkeyote said:

nice work, ive been thinking that my grow box would stay cooler with a 150wHPS with a remote ballast than with the 240watts of CFL's i currently have. Unfortunately, I'm not much of an electrician, and can't find one out of the box at a reasonable price.

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the whole hps disassembly and reassembly was actually very easy. the only thing that i did was remove the photocell, which you can cover with black tape if you dont want to rewire it.

and the making of the remote ballast was even easier all i did was remove the original two wire and replace them with the same wire scheme just much longer.

if you need help man i could help ya out.

this is good info, i want the power of hps with low temps cos im a stealth grower, but i always thought they were a shit load warmer, after my first cfl grow im gonna use a 70w HPS then my current cfl bulbs for bottom lighting. this will be perfect for my own 1 plant grow...

cameron666 said:

this is good info, i want the power of hps with low temps cos im a stealth grower, but i always thought they were a shit load warmer, after my first cfl grow im gonna use a 70w HPS then my current cfl bulbs for bottom lighting. this will be perfect for my own 1 plant grow...

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I thought the same thing until I started messing around with my setup and I realized that I could keep my hand closer to the hps than the cfl's which made me conduct this experiment.

i was planning on making a run to Lowes today anyway....I'll PM ya if i run into any problems,

Sounds good bro.

lowes had a 70w hps for 34 bucks, went ahead and got it, its got a loose white/black, and green which is the ground, i just bought a 2 pronged extension cord, what happens if the ground isn't hooked up?

donkeyote said:

lowes had a 70w hps for 34 bucks, went ahead and got it, its got a loose white/black, and green which is the ground, i just bought a 12 pronged extension cord, what happens if the ground isn't hooked up?

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you dont need the extension cord. i wouldnt recomend using it.

i would take it all apart and get it down to just the mogul socket and the white and black wire.

next take the socket and wire to lowes and tell them that you need the same wire that is connected to the socket, you just want 6 feet of it or more.

then you need to get a small appliance cord. this is what you will use to plug into the wall. the cord you bought is insufficient.

once you get the new let me know and ill help you wire it up.

make sure you have elec tape and wire nuts!

make sure you mark what everything is connected to.

Johnboh said:

you dont need the extension cord. i wouldnt recomend using it.

i would take it all apart and get it down to just the mogul socket and the white and black wire.

next take the socket and wire to lowes and tell them that you need the same wire that is connected to the socket, you just want 6 feet of it or more.

then you need to get a small appliance cord. this is what you will use to plug into the wall. the cord you bought is insufficient.

once you get the new let me know and ill help you wire it up.

make sure you have elec tape and wire nuts!

make sure you mark what everything is connected to.

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I think I'll look into this, nice post.
btw I swapped that duct tape with wire nuts

Right on Nolan. thats a smart move bro! Hows everything looking for you?

Johnboh said:

Right on Nolan. thats a smart move bro! Hows everything looking for you?

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They're doing very good, I've moved them all into 3gal buckets and drilled holes into them but I haven't been able to get ahold of my camera for the past couple days lol.

I'm going to go look for it now actually.

and still, no smell with the carbon filter. I hope it puts through with flowering. haha.

Nolan said:

They're doing very good, I've moved them all into 3gal buckets and drilled holes into them but I haven't been able to get ahold of my camera for the past couple days lol.

I'm going to go look for it now actually.

and still, no smell with the carbon filter. I hope it puts through with flowering. haha.

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you prolly dont need to be using that filter right now. unless your plants are already stinky. should be good till they are at least 8 inches tall

Johnboh said:

the whole hps disassembly and reassembly was actually very easy. the only thing that i did was remove the photocell, which you can cover with black tape if you dont want to rewire it.

and the making of the remote ballast was even easier all i did was remove the original two wire and replace them with the same wire scheme just much longer.

if you need help man i could help ya out.

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i definitely need help with this one.don't wanna burn down the family!!!!!!

https://www.rollitup.org/do-yourself/8499-convert-common-home-security-light.html

They used a 150 watt HPS in that example but wiring is the same for a 70 watt HPS

Johnboh said:

you prolly dont need to be using that filter right now. unless your plants are already stinky. should be good till they are at least 8 inches tall

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They smelled up my entire basement, I started smelling it upstairs.. This was about 2 weeks ago, a few hours with the carbon filter and now only the grow room has a smell. I can smell right outside the vent and its like fresh air haha.
well, there is some duct tape smell. Hahaha.

that link is exactly what i did. haha wish i would of saw it before hand.

what strain are you growing nolan?

Johnboh said:

that link is exactly what i did. haha wish i would of saw it before hand.

what strain are you growing nolan?

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I believe its maui x some strong indica, but I can't remember. It looks great though, I can't wait to try it out! lol

nice bro. sounds tasty!