Sounds a bit steep, even if you are 24/7 with it. But without knowing what you pay per kwh its impossible to say. -OGH
Definitely sounds high. What else is involved electrically with your setup? To work it backwards, if you ran a 400w 24/7 for 30 days that would consume 288 kilowatt hours. For that to cost $100 your rate would have to be 34.7¢ per kilowatt hour, very high.
How do you know the entire $100 boost in your power bill is due to your grow op? August was a scorcher in most parts of the country, maybe your air conditioner was working overtime?
