I do not use any I find them over priced and they tend to contain grass seed of an unknown variety, not great for me when I have to have a specific type of grass to cope with an area having all the top soil removed by the twit before me.
I also spent some time in the far east, over there they embrace moss. I must say if properly shaped and looked after it looks far better than grass!
Back on topic, I would just use a kelp based fertiliser and some Iron phosphate ( the moss killer and grass greener, also used in wool dying and ink!). Cheaper to get them and then make your own mix. I also have fish and the dirty fish water is much welcomed by the grass.
