...think would see large difference by switching out early? "Shaun aRe" <shaun_areaALL_SUFFERINGzenlunatic@beatsSPAMnheat.plus.com> wrote in message news:45ed6a0f$0$8716$ed2619ec@ptn-nntp-reader02.plus.net... From the growell site (more in their paper newsletter about this): "We now recommend that you change your Grolux lamp every crop for maximum efficiency. The cost of a ...

From the growell site (more in their paper newsletter about this): "We now recommend that you change your Grolux lamp every crop for maximum efficiency. The cost of a new lamp is less than you could lose in yield by not changing." (They go on to say that the higher output/different spectrum ballance of Grolux type HPS tubes is at the cost of lower lumen/life than 'std' HPS, as ...