Um, that's not a good smell...

So I finally upgraded to a real HID light setup! Got the Predator fixture, Hortilux Blue 400W and ballast, and a small 65 CFM fan to make a closed loop vent for the light. I still need a small clip fan for the inside, but at least the tent has some vent holes on the bottom sides. Anyways, I had just started it up and it ran for like 3 minutes, then there was this smell like something was on fire, so I freaked out and unplugged everything. I'm thinking maybe the fixture was a little dusty inside, since there's no other signs of damage. Or do ballasts stink a bit when they're fired up for the first time? I dunno, I had decent airflow through the closed system so I'm not sure. Is this normal when first starting up? I guess I'll dust off inside the Predator just to be safe, can't let that lamp get dirty.

It was more of a dusty smell, no sign of smoke, so I guess I'm alright?

I've never had a burning smell. Could have been anything though. I'd run it in a well lit area and check for smoke or something. If you don't see anything immediately then let it run for a few hours. Maybe it will cook off whatever was on wherever.

well it is either dusty or burning... if it's burning then thats bad..

I would be more concerned about the houses electrical wiring,junction boxes and breakers. I honestly dont think dust a tiny bit of dust on a new set up would give you that smell. It really sounds like you could be burning up a junction box . How is the wiring in your house new or old? Has your breaker ever tripped ?

I had a major issue with my electrical when I first started. My house although had new wiring it was designed poorly and all of my major appliances and my setup was running off of one breaker leg and kept burning it up I had to replace the outside breaker and move around the breakers on the inside. To give you some more info A breaker has 4 legs ideally you want your house to be pulling evenly off of each leg. In my situation 70% of my power was being pulled off one leg causing it to burn.

Also most of the time junction boxes are located in the attic I would suggest going up there and looking at your wiring etc and maybe look and feel it when its on put your hand on the box see if its letting out a lot of heat .

yeah you need a much higher cfm fan, 65 is way too little. Im also guessing its the wrong type of fan, which does not have the torque required to push through a carbon filter, or ducting very well. For a 400w light I would recommend about a 200 cfm squirrel fan, or inline centrifugal fan.

i'd hit it with compressed air outside
if you wanna do it well, try taking apart the ballast and wiping dust off, it will help the heat dissipate quicker, and hopefully take care of whatever is smelly.

also look where the bulb's mogul goes into the base, and look for signs of arcing, it will be black. It may just not be contacting causing arcs, any arcing means chance of fire.
good of you to ask, doesn't hurt to be safe right?\

and yes, as others said, make sure if using a HPS cord, you use a properly rated timer, and dont plug the cord into an extension cord with a lower gauge wire (like a lamp cord or some shit)
the cord must be properly rated, and you want to be careful not to pull more amps than the room (or cord) is designed for, because that could cause fire too

same rule applies for all equipment, match the wire's and don't reduce them to a thinner gauge.

hope this helps.

oh yeah a good trick is after you double check all this , let the room turn on for a while.
go back and touch each cord you used, if they are warm (compared to room temp) they aren't sufficient and you need to upgrade them

Your bulb and fixture are just getting hot for the first time and cooking off some vapors. Vapors of what I do not have a clue but lots of electrical stuff throws off a smell till it gets broken in.

To be safe you could stay within close range of the light a couple hours or plug it in in your living area and keep an eye on it for a while.

You can get a smoke alarm for $10-$20 and put it in your grow area. I would definitely recommend doing this. I've got one in mine and hope I never hear it go off, but it's cheap insurance.

I have a green Utilitech extension cord, supposed to be for outdoor stuff, an APC battery-backup outlet, weighs a ton, and had airflow all the way through the loop. My tent is only 20 cubic feet, and the fan was meant for it at first, then I had this idea. I still need a good clip fan for that. Anyways, the breaker box is in the kitchen, so it didn't cause the smell. All of the red ON/OFF switches have the number 20 on them, I guess that's amps? The ballast only uses 4, I cracked open my wall outlet and it's rated for 15. I did have the ballast on this timer switch, idk if it's legit but it's grounded too and seems alright. Here's a pic of it and my fan.

The Predator was actually a floor model that was hanging from the ceiling for years. It was dusty when I got it, but I thought I got it all. Probably not I'm guessing. I'm going to fire it up again and try to localize the smell. It should come out the bottom if it's from that.

Yeah, it's definitely coming from the fixture. Still smells a bit even though I had wiped it off some more. Oh well...

good job

did you inspect the bulb receptacle ? the base aka socket
look for carbon, left from arcing.

aim aim is right all the way , but doesn't hurt to check the extra stuff

I took the bulb out when I wiped down the fixture, but I'm honestly a total noob when it comes to HIDs. It looked normal to me, the socket seems perfectly normal. I fired it up again and the smell was there coming out the back but not nearly as bad. However, I absolutely must find a way to vent the room itself, because even with that closed-loop setup the 400W turns that little room into a nuclear reactor! It got up to 84 degrees in less than 10 minutes, so it's off again. I'm actually thinking of downgrading a bulb size and saving this one for another day. So here's a question to whoever may know: how should I vent this? Can I run an inline out the bottom port? I only have two ports left, a 6 inch one at bottom and like a 2 inch at top. Or should I skip the closed-loop thing and do regular intake/outtake? Regardless I'm going to need another fan...

Keep in mind this box is tiny, 2x2x5. It has two little screens at the bottom with mylar Velcro things you can put over them. I thought that would help with air flow, but apparently not enough!

Yeah, unfortunately your learning the hard way that those small fans are really only good for supplemental air movement. Or in addition to a more powerful fan.

I can see from your picture your venting makes a total of 270* degrees turn in your setup. A 90* degree turn is enough to lose 40% of your air movement in some cases.

I would recommend just biting the bullet and buying a 400 cfm 6" inline fan and a speed controller. Fans get quieter while they get larger in this case. I really wish someone had given me this advice when I started out, I went through 2 of those crappy fans that you have (except 6").

Why don't you just ditch the little tent altogether and grow in that nice closet?

I'm thinking the fan I have now could be run straight into a bottom port as my intake air, 65 CFM. With the right equipment I could place the exhaust fan on the roof port, their 6' has 160 CFMs, which should be plenty strong even when I do get a filter, which isn't needed yet because I have all of two sprouts atm. On my closet shelf next to the ballast, another fan to push that air right out of the room, or I could even install a small ceiling fan in there, it's my house after all. Have to leave the door open when "cooking", but that's fine.

I guess I could ditch the tent, but it's got all that mylar and right in front of this closet is a window that ppl drive by on the regular. I dunno, just wanted a nice contained environment.

This plan sound better? Thoughts?

this plan does sound better. Except for 'upgrading' to the 6" 160 cfm. this thing will not have the required uummf to push or pull through a carbon filter.

Tents are built to have air pulled our from them, creating negative pressure and helping with pest control and climate control. Try and stick to 2 fans if you can, it will cut down on expenses and keep things simple, but seriously just nut up and buy one of these:
http://growershouse.com/hurricane-inline-fan-6-435-cfm

Just FYI this is a great fucken deal, I got my 4" 180cfm for about the same price, I really wish I had just gone with one of these first.

Lysemith said:

yeah you need a much higher cfm fan, 65 is way too little. Im also guessing its the wrong type of fan, which does not have the torque required to push through a carbon filter, or ducting very well. For a 400w light I would recommend about a 200 cfm squirrel fan, or inline centrifugal fan.

Click to expand...

I have been using booster fans for years, works like a champ.