in your opinion

I am wondering if 1 grow room running 1000watts 12/12 would be better than 2 rooms alternating running 400 watts 24 hours ?

I would have two rooms if I had the money and everything. I just think that you can do more with two rooms then just one. Most people have a veg room and a flowering room.

you should convert to beer cups and cabinets, twice the yield and you can really hide it

welcome to the forum. That is a really good question. shows you are putting a lot of thought into ordering your lights and getting set up. Lets see if we can make some sense out of it. Nope, cant make any sense out of it. If you use the 1000 watt light you will have more light and less flexability. It will cost a little more to run and you might not be able to get it close enough to your plants to use the extra light. If you use the 400watt light you will use less energy and have less light. You can put it closer to the top of the plants so at first you may get more light to the plants but as they get taller you may not have enough light to penetrate the canpoy. I think you will be sorry if you plan on using to seperate rooms and moving the light between the rooms. That is a logistics nightmare. It might be helpful if we had some idea of what your overall plan is. how much space things like that. VV

well basically 2 4x4 rooms both with 400watt hps lamps(2 seperate lamps)each on a timer 12/12. now the real question is since i decided this over the 1000watts is... would it be better to run them at the same time which means 800watts for 12 hours a day or run them in conjunction to eachother so there would be a constant 400 watts 24 hours a day?

I would run them at the same time, the reason being is when your time allows, you will want to work in the room(s), it would suck not to be able to work on one cause the lights are off.
When you get your lights, look for those 430 watt bulbs.....the little extra wont hurt ya! Thats about 53,000 lumens.
Peace.

Just curios why would you make it two sepeate rooms? If one is for vegging/cloning then you will want to run that light 18/6. If they are both for flowering having one room will allow better air circulation easier caring for you plants etc. Just rying to get the picture here. You know j=how old people are, always curious. VV

nope all my vegging is done elsewhere, both these rooms will be 12/12 with a divider in the middle which will block the light. The reason i want to do it this way is so that i get to crop out every 2-3 weeks. for heat reasons and venting and hydro fluctuation i was thinking maybe 1 room running at a time and alternating 12/12 so that there is always 1 room going with only 400watts at a time....see what i am saying

got it dude luck to ya.