First time grow. Advice?

Hi guys, i'm about to start my first grow. Iv'e got a neat little indoor setup in my shed I'm planning on using a 600w hps over 5 white rhinos from start to finish, the lamp will be around 3 feet away from the seedlings due to limited space, is that too close and will this be too much heat in such a small space? It's winter here now so the outside temp is around 2c at night inside the shed, if I leave the grow space open to the cool air will that, plus some sort of ventilation be enough to keep the temps down ? I wanna keep the plants short for obvious reasons so how close can i let the vegging plants get the the light without worrying about them burning, should i spend some pennies on a cool tube? Also what kind of light/dark cycle should i consider? Any advice would be sound.

How exciting! Temps are very important. One of the most important tools is a thermometer/hygrometer. They make a digital combo for $12 here in the US, you should be able to find something similar. RH will be a bigger factor later. It will probably be very cold in there when the lights are out, so a small heater may be a good idea. I would keep the bulb exposed for as much heat as possible. Air circulation is important. A small oscillating fan will help build strong stalks. You may stretch your plants with the light too far above. I think the rule is that they are right when you can keep your hand under the light for 30 seconds without getting too hot. Check on that. These things are pretty resiliant. Don't drown or over feed them! They will let you know what they need. 18hr light during veg, complete dark during night. How long do you plan to veg them?

I just realized you are talking seedlings. you should get a small cfl and start them indoors with a dependable climate/temp.

Hi You don't give a size of your shed. I would think 3 ft from seedlings would be good. I'v been told that 66f with lights off. You will want air flow. If the light burns the back of your hand then it's too close for plants. 18 on 6 off veg. 12/12 flower. What are you going to grow in soil and nutes what are you going going use. I'm sure some people will have more help. good luck match

Thanks Bridgette. What do you mean by RH though ? Not sure how long i'm going to veg for, I was thinking of tying the main stems down at and angle to allow for a bigger yield, but keeping the height down and then just letting them grow within a few inches of the light. Does that sound like a decent plan or ?

Foam insulation can be stuck up. Run lights at night to give heat. You may need a heater..

The grow space is about 3x3x3 match. The light doesn't get too hot i left it on for a while today and the temp in the grow space got to around 33c or is that too hot?. I got some decent soil with apparently 3 months worth of nutes in it, sand for drainage and all that good stuff. Not sure of the ph level though. What nutes do you recommend ? I've stuck up reflective radiator insulation dude. Its like a box type deal with one wall missing.

Too hot..82 f is about max without CO2.

RH is relative humidity. It's more important during flower. 3x3x3 is pretty small. You are going to have to LST/lollipop your plant. Running your lights at night is a good tip, so that their dark phase is during the warmest part of the day. There are some great tutorials here. Read everything you can. By the time you have to really start worrying about it, you should have some more specific questions. There are a lot of people here to help; but they aren't doing your grow for you. Take a deep breath and enjoy your first grow!!

i don't think it'll get too hot in ur shed if night temps are around 2 deg C nd for ur plants to withstand the hot temps in the day start feeding them silica it will boost the stem size nd prevent any kind of heat stress on the plants.
the upper limit with day temps should be around 27-30 deg C but its not that much of trouble if u feed 'em silica.
I grew one outdoors nd the daytime temps did reach around 32 deg C while the nights were cold but my girl is loving it also i guess cuz ur doing an indoor setup u need good ventilation thats pretty much it.


PS - Don't overfeed them, happens a lot in first grows. just try and establish the upper bound of ur nute strength but raising the levels slowly instead of a sharp increase in subsequent feeds

oh nd to keep them short try supercropping along with lst (super crop when in veg nd during flowering just tie those resilient shoots down u can checkout a no. of super cropping tutorials on utube)

Peace out!!