I've tried something similar with my chestnut tress, but I'm not using a float valve to fill the gutter with water(looks like you are using pvc pipe with holes drilled in instead of a gutter), I fear that is too much water for chestnuts.
Last year I would add water to gutter manually to water from the bottom, once in a while I would soak them good from the top letting the water drain into the gutter.
This year I think one of my gutter ends is leaking, but we have had enough rain this year I haven't looked into to find out yet.