I cant seem to make up my mind. 600w or 1000w for a 3' 8" by 4' 10" with 8' of ceiling height. 6 ladies would be the max. I dont think cooling will be an issue as this will be a vented hood plus its in a naturally cooler area (basement). My thought was I'm looking at getting a dimmable hps/mh ballast so I might as well get the 1000w right? I could always dial it down to 75% = 750w. I'm pretty much convinced on the 1000w but something is telling me thats a little too much for that space.
600w gets more lumens per watt, but 1000w gets more overall lumens. If I were setting up a room with several lights, I'd go with 600's or maybe 750's. For a single light, go with the 1000w, especially since you'll have a dimmable ballast and can dial it back if you need to for some reason.
I'd personally go with a 600w if you don't mind spending the extra money on electricity a month, With the size room you have and a 600w you will be using 4500 lumans/sqf where as the 1000w you get 6500 l/sqf, and the minimum you need is 3000l/sqf so either choice is way above your minimum. It really just comes down to you and your grow room.
I ended up going with the 1000w dimmable ballast. This isnt my first rodeo so I think I will make use of every lumen I can get. And I always have the option of making a bigger room so the 1000w will most definitely come handy in the future.
I just finished my grow , I was using 600W lumatec dimmable ballast with digilux bulbs.I was able to get over 200 grams of dry bud out of two plants in DWC not counting over 40 grams lost to mold... SO 600W is the good choice, but 1000 even better, as long as you can manage the heat. Congrats on you ballast.
Yeah much better than the 400w I had previously. I will have a 400 cfm inline fan and a vented hood. Plus being in a basement with cooler temps (averaging around 65 degrees) will help.
You'll be fine as long as you vent your exhaust somewhere else. I have a 460 CFM fan for my 1000 watt and my temps under the light at the canopy only gets about 5-7 degrees over the ambient temperature outside of the tent. I usually keep the ambient temps at 75 degrees, that way my canopy temps don't go above 80-82 degrees. Since your ambient temp is 65 degrees you should have no problem keeping it cool with 400 CFMs.
Yeah I will be venting outside the house. It will be filter ---> hood ---> fan ---> 8 feet of 6" duct to outside.