ahh ok then 6 is probably fine (if your sure your medium is 8 ?)
dunno about your nutrients, try google but in most cases, less is more
and I used the 600W sylvia myself with good results before I got the LED panels, as a rule of thump a bulb will last you 4-5 grows ( a year) so I would for sure look in to a replacement bulb, even a budget bulb is better then a warn out bulb, the budget bulb might just last you less grows and might blow on you before a Etc Philips Sylvia
Ooh yea, and if you got the $ get a few, sucks to blow a bulb in the middle of flowering and then have to wait 2 day for a replacement, tho you could use that one you have now as a back up, no matter what I wouldn't like to "wast" my time and money to grow under a bulb I was`t sure of
a few pictures of me measuring the Lumens output of my 600W sylvia bulb with my "cheap" light meter
![DSC00820.jpg](/data/attachments/1994/1994323-aa8c1c8dea245e9cf9a4605c0c5fad07.jpg)
+7K Lumens a ft away and around 5K at the top of my plant`s (got it even close after I got a cool hood on it, could also get them perfect temps under 80F)
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