Again- I'm not familiar w/ this bulb in practice- I'm working from the spec graphs, and my experiance w/ conversion bulbs. For all I know it's a winner.

Most of the conversion bulbs that I've been around lost brilliance fairly quickly, and were relatively expensive. ($53 is a VERY good price for a 400w conversion- I'd def give one a shot.)

Replacing bulbs annually, if yer burning a good ag bulb, should run you about $100 per annum. If this conversion only lasts 6 months, it's gonna cost you $106+tax per annum. 400w conversions are often $100+, which puts cost per annum ( replacing every six months) up over two hundred bucks- prohibitive, to me.

In terms of the bulb, that spec graph looks to me like it's tossing a lot of energy in the 530-540nm range.

If you want the best, in my opinion that'd be the Hortilux Blue- but that's gonna require a MH compatible ballast. This may be a workable option.