i too have been using a similar bulb, it is a plantmax pulse start metal halide 7K kelvin temp 600watt.
i have been using them this time in flower thinking a full on complete spectrum would be nice for resin and buds color, it is day 23 and the buds look like they are 14 days old in growth. but the plants DO look good, but i aint no damn lettuce farmer!! i want to harvest fat sticky buds to smoke. so i switched them out for my ushio 600watt super red HPS and they are already getting right after 36 hours.
they are exactly what krunch is basically using just under a different name and the ones he got are the "original" pulse start pick based on color temperature bulbs on the market. totally shit IMHO
FTP from everything i have read seen heard about the sunpulse bulbs, i really think maybe you are just telling yourself that the yields are solid.
i put that very very blunt, with no intentions of insulting your skill, but just cuzz you spent the major coin these sunpulse bulbs command, dont mean they are good.
i have yet to hear of a good result with sunpulse bulbs, that had accompanying pictures to prove it.
I don't believe those have any added blue spectrum like the hortilux and ushios
not sure, but that's way cheap.