Easy to use soil that will most likely bring you all the way into flower without having to use fertilizer, but if you want optimal results or your plant gets really hungry you'll have to use some fertilizer sooner or later.
The G1500 is a very good lamp, especially for smaller tents like my 60x60cm footprint. It delivered a very good PPDF at not even 100% and when paired with the GGS Controller it's very easy to schedule your on/off time and whatnot. It could definitely also be used for bigger tents.