First real grow in 2x4 tent unsure on Promix Hp and more

Hey, if it ain't broke, don't fix it, right? I actually find it looks pretty clean.
I must say those tomatoes are looking pretty good! Mine are outdoors and unfortunately I'm in a high wind area. About 3 days straight of 60+ km/hr winds have taken their toll on all my garden veggies sadly.

So have everything hooked up just doing a dry run. Temp is stable at 31c from about 8 inches from the light and humidity is 21%.

Think I should be okay sitting around 31c (88f)? Seems a little warm still. The Inline fan I have doesn't seem to be pulling the air out enough even on full blast I'm worried I've got too many bends in my duct work.

Anyways what's everyone's thoughts?

Edit: thinking of returning the 5000 BTU A/C unit I bought and getting a 8000, think that should bring me down those extra couple degrees?

So I ended up getting a nice 12,000 BTU unit for the price of an 8000 so I'm keeping my room at 20c (68f).

I changed around the ducting so I'm venting out the top and have a fan blowing air from the vent to the room. Temp is around 28c (82f), but due to the ballast being messed up I think I'm running on 600 watts. Too scared to mess around with it in case I turn it up even more. If temps are consistently lower I'll shorten the ducting some and hope it increases air flow a little as well.

Anyways the plants went in last night and are on 18/6 at the moment. Night time temps are 22c, just above ambient room temp. I think this is because of the Inline fan inside the tent. I'll look at placing it outside in the near future.

Picked up some Bio Thrive Grow and Bloom, should I get some CalMag as well? And what/when should I start feeding? I gave them plain water today so I'll assume next watering?

So temps have been as low as 23 and as high as 28 in the tent. So I ended up moving the tent to a window and am venting out the window as we speak just above the air conditioner and rigged some cardboard and a small box to use as a flange until I get to the hardware store today. For some reason temps won't go BELOW 28c.

What gives? Ambient temp is 20-22c and I'm consistently getting temps at 28c. Do these lights really put out that much heat? I mean I'm running a 350cfm fan at 80% and it's moving pretty good. Can't understand why I'd still be hitting temps in the high 20s. Is my bulb maybe a POS? To be fair I can't tell which setting I'm on, on my ballast, so I could very well be pushing 660 or 600w.
I've been waiting for temps to stabilize in the tent then I'll try and move the knob lower and see if temps change.

Hashishh said:

So have everything hooked up just doing a dry run. Temp is stable at 31c from about 8 inches from the light and humidity is 21%.

Think I should be okay sitting around 31c (88f)? Seems a little warm still. The Inline fan I have doesn't seem to be pulling the air out enough even on full blast I'm worried I've got too many bends in my duct work.

Anyways what's everyone's thoughts?

Edit: thinking of returning the 5000 BTU A/C unit I bought and getting a 8000, think that should bring me down those extra couple degrees?

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You don't take temps by putting your thermometer under your light fella.

The radiant heat will give you a higher reading, especially with HPS which has a large portion of IR in the spectrum.

There are various temps that are important. But Air temp is what you want to be measuring, to do that you need your thermometer in shade, above the light line ( not directly above light) with a air been well mixed by fans.

Then for plants radiant heat, we use the hand test or we can use a laser thermometer to measure leaf surface temp, the hand test is fine. If you can hold your hand at canopy level without moving it, then that's ok. Plants can take radiant temps of nearly 50 degrees C. Air temps are a totally different thing.

As far as your ballast goes. Does it not click when you turn the dimmer one way or another? I have never seen a free turning dimmer on a digi ballast. You should be able to turn it all the way right for 660w, then one click left for 600, another for 440w and another for 400.

coreywebster said:

You don't take temps by putting your thermometer under your light fella.

The radiant heat will give you a higher reading, especially with HPS which has a large portion of IR in the spectrum.

There are various temps that are important. But Air temp is what you want to be measuring, to do that you need your thermometer in shade, above the light line ( not directly above light) with a air been well mixed by fans.

Then for plants radiant heat, we use the hand test or we can use a laser thermometer to measure leaf surface temp, the hand test is fine. If you can hold your hand at canopy level without moving it, then that's ok. Plants can take radiant temps of nearly 50 degrees C. Air temps are a totally different thing.

As far as your ballast goes. Does it not click when you turn the dimmer one way or another? I have never seen a free turning dimmer on a digi ballast. You should be able to turn it all the way right for 660w, then one click left for 600, another for 440w and another for 400.

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Well shoot that shows how much I know. I put some pots down and will take temps at about 2" up from light level and put a length of ducting to shade the probe.

The entire time since I've set up the tent I've been doing the hand test and when I've got temps of around 25 I'm able to touch the glass without burning my hand. It was quite cool actually.

So I'll take it I am probably good to go then regarding exhaust?

As far as my ballast goes I've got a new one on the way. I went to turn the dial down one day and the knob made an awful noise and then I was able to move it around 3/4 of a turn freely with it clicking sometimes. Hoping my new one will be here by Friday. Is it also normal for these ballasts to be so noisy? It's louder than my damn inline fan.

Since moving the probe and placing it in the shade I've been able to drop the temp to 26c and that's at about 75% power on the fan. Hoping to drop it to around 23.

Hashishh said:

Well shoot that shows how much I know. I put some pots down and will take temps at about 2" up from light level and put a length of ducting to shade the probe.

The entire time since I've set up the tent I've been doing the hand test and when I've got temps of around 25 I'm able to touch the glass without burning my hand. It was quite cool actually.

So I'll take it I am probably good to go then regarding exhaust?

As far as my ballast goes I've got a new one on the way. I went to turn the dial down one day and the knob made an awful noise and then I was able to move it around 3/4 of a turn freely with it clicking sometimes. Hoping my new one will be here by Friday. Is it also normal for these ballasts to be so noisy? It's louder than my damn inline fan.

Since moving the probe and placing it in the shade I've been able to drop the temp to 26c and that's at about 75% power on the fan. Hoping to drop it to around 23.

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With the cfm your running I would expect about a 4 degree rise from ambient temp, I would be comfortable with that temp myself, although I know it seems all the rage these days to be lower than that.

I have had some ballasts hum a bit but it shouldn't be too loud, certainly not inline fan db levels. But that said we all have different hearing and some people are very sensitive to certain ranges so might just be its not as bad.
There could be a fault internally though. They are fairly cheaply made.
The fact that it broke when you tired dimming it doesn't fill me with confidence

coreywebster said:

With the cfm your running I would expect about a 4 degree rise from ambient temp, I would be comfortable with that temp myself, although I know it seems all the rage these days to be lower than that.

I have had some ballasts hum a bit but it shouldn't be too loud, certainly not inline fan db levels. But that said we all have different hearing and some people are very sensitive to certain ranges so might just be its not as bad.
There could be a fault internally though. They are fairly cheaply made.
The fact that it broke when you tired dimming it doesn't fill me with confidence

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Sounds fairly close. Room temp is 23 right now and the tent is now sitting at 28. I keep getting variations between 26-28. Seems a lot of people I've talked to tells me not to even put them in the tent if I can't keep temps at 25c at the canopy.

So I should be fine to go about the way I am then? At least I'm no longer trying to cool down what I was venting out.

Seems like the hardest part for me is trying to figure out these temps. So if MJ can take a radiant temp of 50c how close to the lights should I be going? I've heard generally 12-18 inches for a 400w which is what Ill be running during flower most likely but plan on running 250 until they appear a little happier.

Right now I was planning on placing my seedlings about 2' away. It's somewhere around 30c at ground level in direct light.

I'm beginning to think the ballast may just be messed. Didn't seem as noisy when I first got it till shortly after the button broke. Maybe I'm stuck in super lumen? Guess I won't know till the new one comes in.
What do you expect from cheap China I suppose. On the bright side it doesn't seem to get very warm, so I'm fairly confident I won't end up setting anything on fire... Lol

Hashishh said:

Sounds fairly close. Room temp is 23 right now and the tent is now sitting at 28. I keep getting variations between 26-28. Seems a lot of people I've talked to tells me not to even put them in the tent if I can't keep temps at 25c at the canopy.

So I should be fine to go about the way I am then? At least I'm no longer trying to cool down what I was venting out.

Seems like the hardest part for me is trying to figure out these temps. So if MJ can take a radiant temp of 50c how close to the lights should I be going? I've heard generally 12-18 inches for a 400w which is what Ill be running during flower most likely but plan on running 250 until they appear a little happier.

Right now I was planning on placing my seedlings about 2' away. It's somewhere around 30c at ground level in direct light.

I'm beginning to think the ballast may just be messed. Didn't seem as noisy when I first got it till shortly after the button broke. Maybe I'm stuck in super lumen? Guess I won't know till the new one comes in.
What do you expect from cheap China I suppose. On the bright side it doesn't seem to get very warm, so I'm fairly confident I won't end up setting anything on fire... Lol

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Yeah you will be fine, some folk run mid to high 80s and produce some awesome buds.

The radiant heat is unlikely to cause an issue, but having the light too close will just be too intense light wise, so you can get light stress, bleached buds. But 12" is good for 400w with air cooled lights and lots of air movement. Healthy plants will tolerate any extremes far better than sickly ones.
Seeds been expensive I would start them with a blue cfl around 20w, you can do that in the corner furthest from your light if you cant start them elsewhere. On their own HPS can cause seedlings to stretch considerably. Its possible to do though.

coreywebster said:

Yeah you will be fine, some folk run mid to high 80s and produce some awesome buds.

The radiant heat is unlikely to cause an issue, but having the light too close will just be too intense light wise, so you can get light stress, bleached buds. But 12" is good for 400w with air cooled lights and lots of air movement. Healthy plants will tolerate any extremes far better than sickly ones.
Seeds been expensive I would start them with a blue cfl around 20w, you can do that in the corner furthest from your light if you cant start them elsewhere. On their own HPS can cause seedlings to stretch considerably. Its possible to do though.

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Right on, I shouldn't have to worry all that much from the sounds of it then.

Oh forgot to mention I've got a MH bulb in right now, not HPS. Got that part covered. I'll put the seedlings back in now, the one has started looking quite sickly. The leaves around it are looking odd. I'm almost thinking wind or heat burn or something along those lines? I'll put it back in the tent and see how things go.

So I've been messing around now and ran a duct in front of the AC to feed cooler air through the intake to see if it'll cool things down any as I've been taking temps from in front of my intake, which is located on the back side of the tent and it seems a 18c intake is the golden spot for 25c temps on the tent.

Now given that my intake fan can pull this much (it's 350cfm), could I run my filter and fan as an outtake and run a duct out in front of my AC that goes though my hood/light? I feel like cooling the light may be a little more efficient than trying to cool the ambient temps in the tent.

The ducting would be much smoother than what I have in now with less bends in it, but I'd be running much more so I'm worried about a massive drop in cfm, though it may stay the same as the extra ducting may be offset by having less bends. Other than that I wonder if cooling down these lights with 18c air would be harmful in anyway to the efficiency of bulb?

Mostly just thinking out loud but I may have to give it a try this coming weekend when I've got some spare time and post back. Any input is appreciated!

Hashishh said:

So I've been messing around now and ran a duct in front of the AC to feed cooler air through the intake to see if it'll cool things down any as I've been taking temps from in front of my intake, which is located on the back side of the tent and it seems a 18c intake is the golden spot for 25c temps on the tent.

Now given that my intake fan can pull this much (it's 350cfm), could I run my filter and fan as an outtake and run a duct out in front of my AC that goes though my hood/light? I feel like cooling the light may be a little more efficient than trying to cool the ambient temps in the tent.

The ducting would be much smoother than what I have in now with less bends in it, but I'd be running much more so I'm worried about a massive drop in cfm, though it may stay the same as the extra ducting may be offset by having less bends. Other than that I wonder if cooling down these lights with 18c air would be harmful in anyway to the efficiency of bulb?

Mostly just thinking out loud but I may have to give it a try this coming weekend when I've got some spare time and post back. Any input is appreciated!

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Cooling the light would be waste of ac. Remember your trying to remove the heat that is created from the light before it heats up your space, that's why we use cooled hoods. But there is no cooling the light, it will create the heat it creates either way, so throwing lower temps at your light would be a waste of time.
Use the AC as intake air.

coreywebster said:

Cooling the light would be waste of ac. Remember your trying to remove the heat that is created from the light before it heats up your space, that's why we use cooled hoods. But there is no cooling the light, it will create the heat it creates either way, so throwing lower temps at your light would be a waste of time.
Use the AC as intake air.

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Fair enough, was a thought. I suppose in that case I'll just be pumping warmed up air by the time it reaches the inside of the tent.

I actually ran a 6" duct to in front of the ac and it seems to work great. Temps fluctuate between 22-28 depending when ac is on or off. Pulls too much air in as I had to duct tape about 1/4 of the opening so on my way home from work I'll stop at the store and grab some 4" ducting and run that from the backside.

Will also be putting a wardrobe in the spot the dresser is beside the tent and run the ducting through that in case anyone barges into our room.

I suppose now it's just the waiting game! Hopefully it turns out.

Got my new ballast today... Worked great for about 30 seconds then it arced out and now it won't work anymore. I'm guessing faulty wiring and it shorted out.

Just a heads up for everyone, Vivosun has great customer service but I've got 2 ballasts from them and neither work.

Going to go back to using the old one and run to the hydro store tomorrow and grab a quality one. Any recommendations on affordable 600w dimmable ballasts? Doesn't need super lumens but I'd like to be able to run 250 & 400 watts with it, or somewhere around there.

Can't wait to hear from their customer service now, lol.

Hashishh said:

Got my new ballast today... Worked great for about 30 seconds then it arced out and now it won't work anymore. I'm guessing faulty wiring and it shorted out.

Just a heads up for everyone, Vivosun has great customer service but I've got 2 ballasts from them and neither work.

Going to go back to using the old one and run to the hydro store tomorrow and grab a quality one. Any recommendations on affordable 600w dimmable ballasts? Doesn't need super lumens but I'd like to be able to run 250 & 400 watts with it, or somewhere around there.

Can't wait to hear from their customer service now, lol.

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Vivosun has decent quality junk, lol. Everything I have from them has done me good. Hell I have a cheap $15 4in booster fan from them that's been running for 2+ years with no bearing noise.

SwiSHa85 said:

Vivosun has decent quality junk, lol. Everything I have from them has done me good. Hell I have a cheap $15 4in booster fan from them that's been running for 2+ years with no bearing noise.

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They do. I bought the 600w dimmable kit from them that included the ballast, reflector, bulbs, couple extras, the whole 9 yards and the only issue I'm having is with their ballasts.

Just not impressed that I'm at 2 out of 2 failures with them. They're costing me quite a bit of a headache trying to do something as simple as keep my lights on consistently.

I won't even try to use this one, it ended up arcing out at the plug in and I'm nowhere near an electrician so this one's going to the trash. Electrical fires aren't something I want to play with.

I'll see what their customer service replies and start putting money away for a new ballast in hopes I get one thatll last me this crop at least.

So I got home today about 15 mins before lights on and checked my probe temp. 15c OUCH! Looks like I'll have to slack a bit on the ac during lights out. Maybe I'll get a timer set on it.

So just an update Vivosun sent me yet another ballast. I ended up taking the dimmer assembly off the one that shorted and put it in the one with the broken dimmer switch. Had it plugged in the last 10 minutes and everything seems to be working fine. Hopefully it works for a while cause then I'll have a backup ballast as well. Woohoo haha.

Other than that I believe the girls are having some mild sun burn (leaf edges slightly curling up) or are being affected by low humidity (about 25%) because the middle of the leaf is dipped down as well, kind of like a taco shell, which could be a case of low humidity from what I've heard? Will post pics in a bit once my phone is charged.


Edit: let the ballast fire up on 600w and run for a while. Took a look at temps and they were around 26c. Opened the tent, about as bright as it was before.
Turned it down to 250w, waited a couple minutes, temps were already down to 22c and when I opened the tent it was like the lights were off. No wonder I had a hard time with my temps, I was probably running the full 600w in this tiny tent. Now that I think of it, when the button broke I'm certain I was on super lumen mode and was turning it down to 250w.

Oh well, seems that'll cure lots of the problems I've been having with this grow. Now to just let the girls recover and grow a bit. Second node is starting to come out on one of them. 3 more and it'll be time for some FIM!

Just wanna thank everyone for the tips and help! And a special thanks to the guys that convinced me to vent that shit outside, otherwise I'd still be chasing my tail.