Since I am replacing my aluminum holding tank with a custom polyethylene one its now time to decide where I want the inlet and outlet fittings to be. The inlet is pretty simple on "the top". The outlet can either be on the side at the bottom or also on the top with a pipe going close to the bottom inside the tank. It seems as if the outlet is located at the bottom on the side and you are pumping up to the deck then there is always going to be sewage standing in the hose at least to the top of the tank. Since this is a no-no according to Peggy Hill, is a top outlet better? What kind of experiences do you all have with either system. Thanks for all your sharing of knowledge this is a great forum. For your security this Message has been checked for Viruses as a courtesy of Com-Pair Services!

"John Iott - hotflashrefinishing.com" <hotflash@com-pair.net> writes: >Thanks for all your sharing of knowledge this is a great forum. One further suggestion, courtesy of the guys at Marine Sanitation in Seattle (no relation, just satisfied customers): When you install your tank, give a lot of thought to the vent lines. Typically, the vent is a single small (3/4") line running up from the tank. This is very bad for two reasons: first, very little ventilation can come down the line. This leads to lack of oxygen, and the anaerobic environment leads to big stinks. Second, the first time you over-full your tank (and you will) something, typically toilet paper, will get up the vent line and clog it. This will probably not affect the tank when you flush, but the next time you go to pump out the vacuum in the tank can cause it to implode. Not pretty. Th recommended solution is to put two large-diameter vent tubes in, one leading to the starboard side of the boat and one leading to port. If possible, you should place the tank fittings in opposite corners for maximum oxygen exchange areas. The differential pressure on the two sides of the boat will cause natural airflow, and the large-diameter tubes will not clog. I used two 1"-diameter vents on the new 40 gallon tank I installed and it's working like a charm. The forward tank, a 13 gallon tank which I did not install and which has a single 3/4" vent, stinks like hell and the vent has clogged twice. Just my 2 cents, Scott Welch FirstClass Product Manager www.firstclass.com "The person who makes no mistakes usually doesn't make anything"