URGENT HPS question...

some of you know had issue with stem stretching so i just replaced my flor twisty lights with a 400watt hps and befor the thing even fully heated up i could see some leafs started to all most flip over from what i assume is the extra heat i raised the light a bit but i'm still worryed. Any tips?

They don't generate THAT much heat. How close is it to your canopy? Sounds like you need to back it off a bit. It doesn't needd to be nearly as close a fluros or cfls do. The rul of thumb is to turn your hand backside facing up towards the light at the height of the canopy. If the light is too warm on your hands its too warm for the plants.

well it was where my other lights where here... lemme put up a pics.

where it was


the leaf that started to flip over right befor my eyes

Well if it is really that high above them then I think it is probably just adjusting itself towards the light. In my grow tent I have ducting that goes from outside the tent, through the sealed reflector over my 400w hps, and then more venting out the reflector and out the top of the tent. At the top there is an average 90cfm 120mm pc fan that sucks air and blows it out the top. With that an the weather a nice average like 72 degrees outside, I can get my plants to within 3 inches of the glass on the reflector, which is probably a few inches from the bulb itself.

I'm pretty sure you should be fine.

Ok after a few hours of watching like a hawk they seem to be doing ok... i think there where just like OMFG!!!!!! REAL LIGHT.

HPS systems can produce a substancial amount of heat....do you have a vent system attached to your light?

no it's old school prob made/sold in the 80's just a Extremely simple reflector and the bulb the balist cord is long so it's not even in the same room but that thing dosent seem to be produceing any heat the bulb on the other hand throws out a surprising amount. So i angled the little fan i got in there to blow pretty much directly at the blub.

* correction balist does throw out some heat but not really any radiant heat it's mostly only noticeable to the touch and then it's pretty warm but like i said it's not even in the same room.

I currently run a 400 Watt HPS system....

and let me tell you...It would be impossible for my plants to survive without an inline fan pulling the heat away from my light.

Compared to floros and CFL's, HPS systems produce an incredible amount of more heat. If you take a look at most 400W HPS systems on this website, they have some sort of ventilation system that pulls the heat away from you light. Placing a fan that's directed towards your light is not going to cut it. It's simply not enough. Now that you've gotten yourself an HPS system, you need to invest in an Inline fan. They sorta go hand-in-hand. The Inline fan will suck all that heat away from you light and dump it wherever you choose to vent it. Just make sure you find an Inline fan that has a CFM ratiing of 300 or more.

By the way, do you grow in a grow tent? or grow cabinet? or are you growing in an open area that has access to fresh air?

Well i'm pretty bummed now.. gonna have to rip that hps out just opened the door and got blasted with heat....sucky thing is it's a closet with no real way to vent it at all except keeping the door open/ i pretty much do when i'm awake any way.. but now i'm pretty sure it's to hot to keep the door closed when i sleep just put a thermo in there and closed the door for like 10 mins allready to 85°
here lemme post some pics so you can see what i'm dealing with.

inside tops lights there been replaced with 400w hps

outside with door open

90° now and still gonna rise i think sucks too cause the room the closet is in has a ac unit running all the time pretty much set for between 70° and 75°


Anyone got any DIY for cooling a Hps? i don't really want to/can buy a cooling system for it... kinda moot if i can't really vent it i guess :/

Found some stuff on cool tubes but they all require glass/pyrex tubes i was hopeing i could getto rig something i guess i'm just screwed.... if i had any money i'd have a sack right now and not trying to getto rig myself some meds


*update* door open temp seems fine steady at about 81°

well i had an idea that might work for me and i figured i'd post it to help other poor people out there.
i put both of the clamp lights with the flor twistys bulbs back in on eather side of the HPS hood and i figured when i'm here alot of the time just leave the door open when i wanna go out or go to sleep just turn off the hps and switch to the flor twisty's :/ better than ripping the whole hps out and not getting any of the light from it i guess.
lemme take pics

here is the top of the hood so you can see i donno why really


and here is eather side of it with lights off and ready for when i go out/go to sleep i guess


good idea bad idea?

bump.. i think i figured out a way to vent it but i'll have to get back to you when i got it all planed out in the mean time any comments on that last idea? ^

i had an economy reflector my first grow in a closet... it was 400watt hps/mh... i hated that damn light bc of its heat... there is no good way to vent to heat with those lights... they are good for open rooms and cold climates... but inside a closet you might as well just through in the towel... its going to constantly cause you to move you fans, opening doors, running the ac... but what i did was get some of that hard duct work and run it from my AC duct to directly over my plants... it worked.. and about the light leaks... you can build a door way cover out of duct taped card board and fit it into the door way and seal it with tape... then cut round holes into the card board for the duct work... unless you can just cut a hole in the door... replacement door arent that much really but concidering you dont have the money for an aircooled light or dont wan to spend the moeny on one i doubt you want to buy a door... any way im like McGiver bro hit me up on my thread if you need more help.....

thanks for the post Amph... all night i was looking up ways to do it and i found alot of DIY's for things like cooltubes all having the issue of needing some type of glass/pyrex ect tube....the duct is cheap and a non issue and i have tons of pc fans for the air flow. BUT i find some cool videos and ect on taking bottles and using scoring heat and cold if you do it slow steady and carefully you can get pretty good cuts.. All i need to now is find a big enough clear bottle or glass for the bulb to fit in then i'm in business

i'll keep posting on progress if anyone is interested

Kode said:

thanks for the post Amph... all night i was looking up ways to do it and i found alot of DIY's for things like cooltubes all having the issue of needing some type of glass/pyrex ect tube....the duct is cheap and a non issue and i have tons of pc fans for the air flow. BUT i find some cool videos and ect on taking bottles and using scoring heat and cold if you do it slow steady and carefully you can get pretty good cuts.. All i need to now is find a big enough clear bottle or glass for the bulb to fit in then i'm in business

i'll keep posting on progress if anyone is interested

Click to expand...

i learned how to do that in SAPPER school in the marines with a wine bottle, hemp cord, carosine, a lighter and cold water... takes practice...

Yeah i saw it done a few different ways fastest twine/string something like that soaked in lighter fluid or alike tied tightly around area you want to cut... light on fire slowly and steadily rotate bottle till flame allmost goes out then immediately dunk in cold/ice water and it should fracture along the line pretty well.

But i was watching a vid of a guy all he did was Lightly score the line you want to cut on (deep score line is not really better or so he says) then just SLOWLY pour boiling water over the score line then put under cool/cold running tap a few times and boom it pops right off ( better edges than all the other vids i saw with string fire icewater method)

damn man this HID heat shit sucks...I bought a 250w hps off my buddy about a month ago thinking it would be the shit. Got up past 90 degrees in no time and my area does seem that much smaller than yours. I have the HTG supply kind with the separate ballast, and even with the ballast outside the room it was getting way to hot. Nothing I could do about it so I had to scrap the idea. I'm growing outdoor, but it would have been nice to start them inside with the HPS rather than this shitty T8 fluoro setup I'm stuck with now. Good luck.

One suggestion would be to keep the door cracked like you were saying and just end the light cycle right around the time you go to bed. That way the light won't be bothering you when you're trying to fall asleep.

well after looking around the place for idea's i came across a large thick plastic gatoraid bottle the gallon ones. Has anyone every tryed makeing a cooltube with thick plastic like that instead of glass? i know it's not ideal but if it dosent melt i don't see why it would not work.

after looking online at gatoraid bottles i can't find one like this so i took a pic to show you not sure they make em like this any more.