Growspace temp too cold...any ideas?

I recently upgraded my small garage growspace to include a 150w HPS. Problem is my garage is not climate controlled and due to issues this is the only space I have. Even though I live in Florida sometimes the temps will dip into the high 30's and I can tell this is affecting my plants. The lights generate a little heat but not enough and my growspace is 3'x4'x4' tall. Any suggestions on how to warm them up without creating a fire hazard or jacking my electric bill?

A space heater will do. Not sure you have many other options. Putting it a closed space like an inverted trashcan would allow that light to warm the plant more. If you still can't get temps above 50 then a space heater is a must, in my opinion.

Over here in the uk winters are fuking freezing what i do is get a small fan /heater combined put them on a timer so it comes on from say about 5pm for 20mins and then set timer for it to come on several times through the night when temps at its coldest it will cost a little more but its either that or your plants will suffer god luck.

I live in a country where it is constantly cold, and temp is an issue for my ladies.

I have a Tubular heater 60W in my grow tent, and have it plugged into a thermostat , it switches itself on when the temp within the growtent drops below 21C, a little tublar heater this size does the job, as I check temp every day, Min is always floating around 19.9C to 21C.

If you are running a RVK fan for venting, then you might consider running the fan on for 15mins per hours during the lights off period.

Hope this helps

Tubular heating are offen used in caravan or bathrooms for heating! and it should not cost you a fortune in electric, pretty cheap to run

and concern regarding fire hazard, there is also a Tubular guard you can buy for that piece of mind http://cgi.ebay.co.uk/Tubular-Tube-Heaters-1FT-60Watt-ESaving-Electric-Heater_W0QQitemZ120347333529QQcmdZViewItemQQptZUK_Home_Garden_Hearing_Cooling_Air?hash=item120347333529&_trksid=p3286.c0.m14&_trkparms=72%3A1298%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318 & http://cgi.ebay.co.uk/60W-TUBULAR-H...14&_trkparms=72:1301|66:2|65:12|39:1|240:1318

good luck!

oh, just a thought, if the temp is that low, then you might want to pop a thermometer and a tank heater in the rez if you are growing in hydro or aero, with soil they should be fine

Just thought I'd throw in a few pics and see what ya think of my progress so far

put the lights on at night (when its coldest) and off during the day. a space heater with a thermostat will solve your probs

i use a kerosene lantern or greenhouse heater in my workshop, they emit around 1800BTU, and being as youre in a garage light shouldnt be a prob if you have it on low-med.
average fill lasts around 9days depending on the model of greenhouse heater, or 2 days on low for a lantern, cheap to fuel and throw out plenty of co2

same thing happened to me in the last few weeks. the temps at night in the flower room were 42-46f with lights on it was only getting to 65. i closed off the room and put insulation around the box and the temps with the light on and fans running now is around 80 it seemed to work before the lights went on the other day the temp in the room was 60 but thats better than 40's