I built a GRP 30 ltr composter with a separate 5 ltr urine bottle, top off a normal size Porta Pottie use it on a live a board. Has a permanently wired in computer fan for positive pressure and to aid in composting. Get about a month use out of the main vessel before it needs emptying with the two of us using it every day. Separates the No. 1s & 2s, No smell No problems, had it for about 6 months in tropics and semi tropics. Would not go back to holding tank
. Wife loves it for that reason alone.