30x18x36 inch grow tent with 400 watt hps/mh light too hot?

I use a 47Width x 24Depth x 59height tent with a 400 watt air cooled light with two clip on fans and an extraction fan with Air flow: 105.10CFM/88.76CFM.. so my setups pretty similiar and this keeps temp at 75F..
Maybe grab a tent a little bit bigger just to be sure??

 

It's going to be tricky to use a 400w HID in a 3' tall tent. You'll have to be a master at training the plants. The tallest tent you can afford/fit makes life easier...

 

Listen to andyGROW and get a taller tent or smaller light. 

 

I recommend a taller grow tent heres one I found, it's a little bigger than the lighthouse hydro grow tent
 
http://microgrowcentral.com/apollo-horticulture-cheap-grow-tent-2/

 

I would look for an IPower 400 watt switchable digital ballast system  I have one I bought last year for about 120 bucks.  Awesome.  It switches from metal halide to hps by merely switching the bulbs. (included).  Also it switches to 200 watts 50%, 300 watts 75%, and the max of 400 watts.  Comes with hangers, chain reflector.  Very nice unit for the money.  Replacement bulbe are under 20 bucks.  hope this helps

 

The hood I use is only about 18" wide.  If you set up your fan....Wait a minute..Is this a vortex style fan, or a duct booster fan?  A vortex 4" will do the job. It is a matter of hooking it up to a generic in line thermostat.
 
Let me know.  If you do not know what you have;  Post a smapp image so that I can identify the fan.  Glad I could help

 

Perhaps you should into a 250 watt lamp.  I thought about your 3 foot high ceiling.  If you are in AC or will have cool air available to draw in, makes all the difference as to which way to go.

 

You won't have any headroom for your plants...a tiny pot is 8" high, light and reflector a min of 8" high, and a minimum 6" distance from the top of plant to the HID bulb.....in a 36" high tent you've lost a minimum of 22", leaving you with enough room to grow a 14" plant...thats a tiny plant. If it were my tent I'd get a few 2' t5's.

 

If I had a tent that small, I'd use it only for bonsai's. 

 

Scrog it !

 

If you get the digital lamp that you can switch to 50%;  You will most likely be OK as long as you pay attention to detail; Day after day.  %0% is 200 watts.  I believe with active fans, toy can work it out.
 
I will advise this:  You have a very short grow space.  Read up on LST, and options ot keep your canopy lower.  Or;  Buy a 6' tent for bloom.  Use the smal tent you have fro veg.
 
How about this.  You can wait until you see that your plants are healthy and vibrant in the small tent.  At that time;  You may be willing to invest in a taller tent.

 

The fan you have will work for this small space. Keep in mind that ventilation and refreshing air is crucial in the tight confines of a frow tent.

 

Ok running a 400w lamp at 50% is like laying down and pissing vertical.
 
Get the lamp but take the tent, roll it up like a used condom and stuff it in the trash. (no just put T5 or small LED in it as a veg/clone tent)
 
Bigger lights for the win, tents need lots of air flow and small tents work for floros for vegging babies and clones.
 
Do get a bigger space for plants, when you are concerned with a 400w being to hot the tent is too small.
 
A 400W is a runt light, I have 3 and never use them. I have (2) 1,000w I dont use too.
 
Give the tent and old lights to a friend who wants to grow, karma! It will return 10 fold.

 

My cloner wouldn't even fit in that thing.
 
Everyone says you need a bigger tent. even you think the smallest of lights would be too much. 
Do yourself a favor. look up craigslist for a nice size used tent if your concerned about the $.
If it's space your worried about, then growing is not very high on your priority list.  
 
I took over a extra bedroom for cloning and mothers, I built my 12x25 growroom. growing comes first for me.

 

That is because, I am not trying to change your concepts.  I am just trying to help.  I find that answering members questions do help.