Help! New to hps - distance/heat concerns

Dr. Doob

Dr. Doob

Member
I used a 300w led on my last grow, the results were 32g of dry bud, great quality but just tiny buds. Thought I'd give hps a go to see what differences there are aside from the obvious bigger yield. My set up is a 60x60x150 tent, lumii 600w hps dimmable ballast, RAM carbon filter attatched to a 4" RAM extraction fan, 6" rotating fan, soil/perlite mix, 17L pots, biobizz nutrients. 2 fems.
I was planning on only using the hps at 400w due to what I've read about heat problems but if anyone disagrees tell me please.
How far would anyone recommend keeping the hps lights from the canopy top?
 
Headgrinder

Headgrinder

Well-Known Member
I've ran a 400 watt hps in a small bathroom back in the day. I would estimate the size to be, maybe the same or a little less square footage. It kept the room probably about 75-80, but it was in a basement so the room was a little on the cool side to begin with. If you have any kind of air exchanging in your tent, even through a venting flap, that will make a big difference. So with your fan you should be golden. 5x5x12.5 is a nice sized tent. One thought would be run your led, add your hps and dial it up until the temp gets too high. This wouldn't give you the side by side comparison, however usually a plant will use what it wants/needs, so maybe if there is a benifit from the hps it will be apparent even with the LEDs. You can keep the hps as far away as you want, they dont lose their intensity within reasonable limits. Good luck.
 
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Mak'er Grow

Well-Known Member
400 watts still gets very hot.
In your 2' x 2' tent (guessing your talking cm, not inches) your probably going to need a hood with exhaust fan or temps will be 100+
I tried a 400 watt MH years ago in a 2'x 8' enclosure and temps were around 100 if I remember correctly...without an exhaust hood.
Probably best to do a trial run of just light in the tent for an hour or two before you put anything else in...besides fans of course...lol
And remember to match the setting on your ballast to the bulb used...you cannot use a 600 watt bulb with the ballast set to 400 watts.
And btw...your 300 watt LED may not be 300 watts...check the draw from the wall it uses to get an accurate wattage reading.
 
Headgrinder

Headgrinder

Well-Known Member
Mak'er Grow said:
Thats a pretty small bathroom...2 feet by 2 feet...where does the toilet go ? :P
I think its cm due to it being "150", which would be 12.5 feet in height.
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if we are talking centimeters, then that would be alot of juice. You are right...and a tiny toilet. (I'm not very good at math). Dr doob is it a terrarium?
 
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Headgrinder

Headgrinder

Well-Known Member
Mak'er Grow said:
60cm=23.622"...so it would be 23" x 23" x 60" approximately.
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Nice that is right. I divided those numbers by 3.7, I'm glad your on top of it. Because I'm apparently just pulling numbers out of my ass...centimeters sounds right. That would be a lot of heat I would agree. My experience with that would be the back of a closet where I used a 70 watt hps which was plenty, but with a fan it didnt get too warm.
 
Dr. Doob

Dr. Doob

Member
Mak'er Grow said:
400 watts still gets very hot.
In your 2' x 2' tent (guessing your talking cm, not inches) your probably going to need a hood with exhaust fan or temps will be 100+
I tried a 400 watt MH years ago in a 2'x 8' enclosure and temps were around 100 if I remember correctly...without an exhaust hood.
Probably best to do a trial run of just light in the tent for an hour or two before you put anything else in...besides fans of course...lol
And remember to match the setting on your ballast to the bulb used...you cannot use a 600 watt bulb with the ballast set to 400 watts.
And btw...your 300 watt LED may not be 300 watts...check the draw from the wall it uses to get an accurate wattage reading.
Click to expand...
Yes you’re right, my 300w led is actually only pushin around 140w (thats being generous lol) .. my exhaust fan is quite strong as it sucks the tent inwards a bit so was thinking that much air being exchanged along with my 6” rotating fan inside should be enough for the heat, shall do a test today to see how hot it gets in there.. and yes using cm also to measure.. the tent is a secret jardin
 
Dr. Doob

Dr. Doob

Member
Mak'er Grow said:
400 watts still gets very hot.
In your 2' x 2' tent (guessing your talking cm, not inches) your probably going to need a hood with exhaust fan or temps will be 100+
I tried a 400 watt MH years ago in a 2'x 8' enclosure and temps were around 100 if I remember correctly...without an exhaust hood.
Probably best to do a trial run of just light in the tent for an hour or two before you put anything else in...besides fans of course...lol
And remember to match the setting on your ballast to the bulb used...you cannot use a 600 watt bulb with the ballast set to 400 watts.
And btw...your 300 watt LED may not be 300 watts...check the draw from the wall it uses to get an accurate wattage reading.
Click to expand...
I didnt know that about the lights, i thought i could use the same lumii black 600w bulb on the lummi black ballast at any setting? (250/400/600) do i really need the different bulbs for it?
 
M

Mak'er Grow

Well-Known Member
Dr. Doob said:
I didnt know that about the lights, i thought i could use the same lumii black 600w bulb on the lummi black ballast at any setting? (250/400/600) do i really need the different bulbs for it?
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I can't say 100% yes, due to I don't use HID anymore, but 99% sure you do.
I think it is made so you can just change the bulb to suit your need without having to change out the ballast too.
Maybe another grower can help... @Renfro may be able to help...he is very wise on HID. :)
 
curious2garden

curious2garden

Well-Known Mod
Staff member
Dr. Doob said:
I didnt know that about the lights, i thought i could use the same lumii black 600w bulb on the lummi black ballast at any setting? (250/400/600) do i really need the different bulbs for it?
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Nope, as long as you have a digital ballast you're good. Although you will need an air cooled hood to draw air through to cool the bulb and cool your grow. They look something like this. Make sure you get one that will fit in your space. Make sure you set up your fan to pull through your set up.
1583077665592.png
 
Dr. Doob

Dr. Doob

Member
Just using normal reflector hood, think i should be ok with my extractor and rotating fans doing their thing. Anyone have a rough idea how much yield i could get with this setup? Tropicana banana by barneys and skunk#1 by sensi seeds; just one of each
 
curious2garden

curious2garden

Well-Known Mod
Staff member
Dr. Doob said:
Just using normal reflector hood, think i should be ok with my extractor and rotating fans doing their thing. Anyone have a rough idea how much yield i could get with this setup? Tropicana banana by barneys and skunk#1 by sensi seeds; just one of each
Click to expand...
Like I said you need an air cooled hood. Otherwise invest in better LED tech. There's some really good stuff out there. I use HIDs almost exclusively in Secret Jardin tents and full rooms (tentless). With the tiny tent you are in I can't imagine you can run any HID (my 250 was to hot even with massive exhaust for a 2' x 4' tent.

As for yield that is a function of light and grower skill. Welcome to the matrix.
 
Dr. Doob

Dr. Doob

Member
Flipped to 12/12 on monday and swapped my led out for the hps.. Temp sitting round a steady 30 Celsius, with a 12inch oscillating fan and extractor on.. Ladies both look great but still a tad concerned, anyone any extra advice on how to bring it down even 1/2 degrees?
 
A

Atahan

Member
I have a similar problem. I just upgraded to a SJ 90x90 tent and an exhaust fan still couldn't get the degrees steady around 27 Celsius, it always fluctuate between 26 to 30.5 Celsius.
I was wondering if you were able to get degrees down, whether if you used insulated ducting and did ladies show any signs of stress because of the heat.
 
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