How must yield

The old grams per/watt/month
If your good you can get around 0.5 grams per watt month
1000 grams /1000 watts / 2 months bloom = 0.5 g/w/m
Note time is part of the math.
The best I have seen and believe was TIC on overgrow got 0.6 with a scrog system.
Note that is dried,cured, clean
Must admit my average is 0.468 gwm
When you have dreams of trimming pot, to lazy to pick a popcorn bud, then you have down, to doing it right.
Having fun does help, REMEMBER NEVER TELL ANYBODY YOU GROW, OR ANYTHING ELSE.

Help ,e here before I set this up I am worried about the bill. I can't choose between the 600 watts and the 1000 watts. With a big grow like this wouldn't my electricity bill skyrocket. Which is the better lamp for to keep the bill as low as possible.

How far is from here to there??
If you turn off all non use things thats,lots of saving , printer, tv, vcr, etc MOST are on hot standby and use WATTS
Remove all reg light bulbs and replace with florsents, you bill will drop a bunch.
600 watts is about 40% less than a 1000 watt.
Wheres the break even point , how much can you bill/watts go up. Rule of thumb PAY you bill on time.
Remember its best to grow for years , than go with higher watts.
Try this tell your neighbors whats your power bill been, that will give you a start number.
Things that add up , ballast, fans, pumps. WHAT WATTS is where its at !!!

Thank you

1000 watts ~ 2 computers + monitors = 1 small/medium AC