NOTE: Stainless tanks don’t like chlorine, so be sure to rinse thoroughly and then leave the cleaned tank open to air exposure for at least an hour after treatment.

It"s a good idea to purify water tanks periodically to eliminate foul odor and rank taste. Here"s how: Empty the water tank, and than pour in a mixture of water and chlorine bleach in a ratio of one cup of bleach per 50 gallons of water (you do the math for your water tank) until the tank is nearly full.

Slosh the solution around (take the boat out for a bumpy spin, or tow it down the road in such a way that will slosh the water in the tank), and run water through all faucets and shower hoses, then drain the tank. Rinse the tank and faucets several times until all hints of chlorine flavor and odor are removed.

Boat Fuel Tanks and Systems
Raritan Tanks

Fuel Tanks

Boat Accessories - Fuel Tanks

Raritan offers over 200 sizes and shapes of only the best quality tanks , extra thick-walled, 3/8" (.9cm) minimum thickness, seamless polyethylene holding and water tanks.

Raritan - Holding & Water Tanks & Accessories

Raritan Tank Products include Compact Holding Tanks,

Custom Holding Tanks, Tank Monitors and Tank Accessories.


Polyethylene is the only choice for sewage holding tanks because urine is highly corrosive. Polyethylene tanks won't corrode, leak, shrink, bulge or crack under the weight of sewage and also won't permeate with sewage odor.

You've probably read or heard, over and over again, that the key to odor control is the "right" hose, that the "wrong" hose permeates with sewage and causes the system to stink. That's folklore…a little truth coupled with a lot of misunderstanding. The real key to odor control is in knowing how to incorporate proven sewage management principles-the same ones used in composting and sewage treatment-into the installation of the entire system. What very few people in the marine industry have learned, and why there is so much folklore about odor, is the very nature of sewage itself and how it breaks down, what creates odor and what prevents odor from forming. Once we understood these principles and learned how to apply them to onboard systems, we were able to install systems that are completely odor-free and correct the ones that weren't. Once you understand it-and it's so simple!-you can do the same thing.
There are two ways to deal with holding tank odor: try to reduce it, mask it and contain it after it's formed, by using chemicals and filters-which has never proven very successful…or prevent odor from forming in the first place.

In the holding tank, the key to odor control is the vent line; it must allow a free exchange of fresh air for the carbon dioxide generated by the sewage. Therefore, those bladder tanks which have no vent are all but guaranteed to stink; there's no source of air into them at all. Boat builders, boat owners and boat yard personnel who install holding tanks have always viewed the vent line only as a source of enough air to allow the tank to be pumped out without collapsing and as an exhaust for methane. (Many even believe methane-which in fact is odorless-to be the source of odor.) Some take the attitude that tanks must inevitably stink, so the thing to do is run that vent line as far from people areas-cockpits, sun decks, etc.-as possible, or make the line as small as possible, or install a filter in it. All of the above actually create the very problem you want to solve.
Think of the holding tank as a stuffy room which needs to be aired. You know that even if there isn't a hint of a breeze outside, just opening a window will allow the fresh air outside to exchange with stuffy air in the room. Open another window for cross-ventilation and the air exchanges even faster. However, just opening a skylight accomplishes nothing unless there's also a mechanical means (an "attic fan") of pulling the air up and out-and that won't work unless another window is open to create airflow. But the only "window" into a holding tank is at the end of a "hallway"-the vent line. If that "hallway" is too narrow and goes around corners, takes a long and curved path, or rises more than 45 degrees above horizontal, no ambient air can find its way to the tank to dissipate and exchange itself with the gasses in it.

Custom Holding Tanks

Top quality, thick-walled seamless polyethylene tanks won't corrode, won't leak, won't bulge or crack under the weight of sewage and won't permeate with sewage odor.

Top quality, thick-walled (minimum 3/8") polyethylene custom fitted to suit your installation.
More than 200 rectangular shapes and 100 non-rectangular shapes to choose from.

Compact Holding Tanks

Five gallon capacity, adequate for a typical boating weekend.
Designed to fit around Raritan's Compact II, PHII, PHEII and other competitive manual marine toilets.
Portable or permanent model.

Hold'n'Treat system by RARITAN - Holding Tanks & Marine Sanitation


530 Orange Street
Millville, NJ 08332 USA

Phone: 856-825-4900
FAX: 856-825-4409


How to make boat holding tank constructed of plywood with multiple coats of epoxy resin.