Sognare - a satisfied Kiwi boatie
"And then, of course, the bane of every boat owner’s life: a blocked holding tank. Because the aft head holding tank drains overboard using gravity (as opposed to the front tank which is electrically pumped overboard) we thought we were letting the tank empty while we were out sailing, but of course there was no way of really knowing! Then one day we started seeing sewage seep out of the vent! Oh crap. Literally. At this point we hadn’t had the broken deck access to the waste tank fixed so we couldn’t pump the tank out at a pump out station either. We used the front head in the interim while we figured out what to do! We finally got in touch with a boatbuilder who had the time and was happy to replace all our deck fills. Once we could access the tank from the deck side we managed to solve our problem – we jammed a hose in there and used pressure to remove the blockage – which partially solved the problem. Since then we discovered a miracle product called Zaal Noflex Digestor from General Marine Services at Westhaven, Auckland which actually reacts with the sewage and eats away at anaerobic sludge to drastically reduce odours (no more aft head smell! Yay!) and stop these blockages. The by-product is baking soda, so there is no negative environmental impact. It is rather expensive at around NZ$50 a bottle because it has to be imported from Canada – yes we looked at bringing it in ourselves but unfortunately it is classified as a dangerous good which has many too shipping implications. Despite the cost it is 100% worth it, and we find we get at least a month of use from one container, depending on how many days of the month we are home and using the toilets"
Sognare, 17 October 2017