For those wondering about how many lumens, you should be using par meters as they pick up spectrum the human eye can't see. That being said it's much cheaper to get a lumen meter. Over been using one for 15vyrs. I use a 1000 watt hid system and my lumens are as such: seedlings 5k, I gradually raise my lamp about an inch and half a day. In veg I'm looking for 25-40k lumens. During bloom I get 40- 65k lumens. This is perfect in my opinion. Keep in mind its a 4×4 tent with a 1000w mh/hps. I get 14" colas with zero larf!! Hope this helps
