When I was searching for boat inspection plates amazon example I saw a review where someone had bought one to install in the top of their RV fresh water tank to make cleaning inside easy. I thought it was a wonderful idea, so I bought an extra, but now that it is getting close to spring, I am having second thoughts about installing it.

A bit a quick details, fresh water tank is located under bed in tow behind camp trailer. The bed lifts to provide access to the tank and additional storage. The water tank is about 25 gallons, 12 inchs tall, and about 2 foot by 3 foot square. I drain it before winter storage, and run RV anti freeze through the entire system. The tank is semi transparent plastic. I general travel with a full tank of fresh water, unless I know there is potable water at my destination.

I was planning to cut a hole in the top of the tank, just like for an inspection port, this would allow me to reach in and scrub the inside of the tank, rinse it out, and flush the system with clean water.

The standard alternative is to fill the fresh water tank with bleach and water, drive around to try and slosh the water around, flush repeatedly, and sometimes use backing soda to get the bleach taste out of the water.

Being able to reach in and clean will make it quicker, easier, and probably more effective to clean the inside of the fresh water tank.

The inspection port is designed to keep water out, so I think there is some risk that sloshing water, or overfilling could force the inspection port cover off. As I would not realize until I stopped, meaning several gallons of water could be sloshing around outside of the tank and inside the camper/trailer.

Are there any examples of this working well or failing miserably? Are there known good solution to provide cleaning access inside of a fresh water tank?


1 Answer 1


What you propose is widely used where I live - although the tanks tend to be installed under the trailer with an access hatch though the floor, so a bit of leakage is not a major issue.

The correct type of hatch should be fine - the screw on lid is pretty secure. A good sealing system compatible with the tanks plastic is needed - you might need to install a strengthening ring around the inside of the hole depending how flexible the plastic in the tank is. (Sealer does to not adhere to some plastics, so it needs a clamped gasket seal). The only thing to check is the hatch lid has some kind of gasket or O-Ring to seal it. The tank should have an air vent so there should not be a lot of pressure in the hatch - especially if you install the hatch in the center.

As far as cleaning the tank should not need much. You can reduce the need for it by filtering water as it goes in and only filling from clean town supply water.

As far as cleaning it out I rely on Milton baby bottle steraliser - (Active ingredient Sodium dichloroisocyanurate), as I know its safe. I don't like putting 'bleach' in tanks - as 'bleach' often contains other chemicals. I fills and drain the tank a few times as fast as can about twice a year.

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