Filling fresh water tank

Ginther wrote:
I bought one of these a year ago and it has worked great. Accurate too.

Water Meter


My fresh tank is supposed to be 68 gallons. I have NEVER needed that much water in the tank since we haven't dry camped (yet).

I usually travel with about 10-15 gallons in case we need to make a roadside pit stop / repair / clean up ....

Like others have said WATER = WEIGHT

In this case less is better.

Traveling with 15 or 20 gallons of water is one of the worse things that you can do. Either fill the tank or travel with 5 gallons of water or less. With 15 to 20 gallons of water, you have 75 to 100 pounds of weight slamming side to side and front to back. Really hard on a plastic tank and flimsy hold down screws. A full tank is stable and 5 gallons or less is not enough weight to do any harm.

Different answers depending on the unit. If you have a gravity fill type where you can stick the hose in the hole and fill you generally will have an air vent right there at the fill point. When it is getting close to full it will start spitting water at you. At that point slow down your fill rate to get in as much as possible without getting soaked by the overflow. If you have a hose end connection where you screw the hose on you will generally have overflow tubes/hoses coming out under the trailer somewhere. When the tank is full, water will start coming out of these. If you fill it and then start driving you will also see water coming out of these quite often.

And the winner is D1krueger!!

I found the best way to fill my toy hauler tank is from the bottom up. The problem is that it takes to long to fill slowly from the filling tube furnished from the manufacture. I fitted a hose fitting to the fresh water dump exit pipe. I attach my hose to the dump pipe and remove the original filling cap, as it now will act as large vent. I can fill with my hose tuned on wide open. When the water overflows from the original fill tube I know I am completely full. I also use the JAKmeter to monitor my fresh water tank level and always know EXACTLY how much water I have used and have left.

I bought one of these a year ago and it has worked great. Accurate too.

Water Meter


My fresh tank is supposed to be 68 gallons. I have NEVER needed that much water in the tank since we haven't dry camped (yet).

I usually travel with about 10-15 gallons in case we need to make a roadside pit stop / repair / clean up ....

Like others have said WATER = WEIGHT

In this case less is better.

I used to jam a cut off hose down the inlet then wait for the backflow to know it was full. Had the water on too high I guess and more then once the backflow pressure blew off the hose that connects the inlet to the tank. Found that water pools up on the underbelly cover quite nicely soaking the bottom layer of plywood. Got to have overflow capacity equal to or greater then then inlow rate. Need to get one of the shutoffs bpounds shows for better hose end control.

I have no trouble with the fresh water tank level gauge. When it reads F for full it's pretty full except being a few gallons shy of overfilled. It's a different story for the grey and black water gauges. The various chemicals in those liquids tend to make the gauge sensors in the tank inaccurate.

I walked away while filling the tank once (was just in the trailer). After a bit I heard a loud thump & the sound of running water. I then had the pleasure of removing the underbelly cover & tank, having the tank welded & replacing the whole thing. So, I don't walk away while filling anymore.

Just watch the overflow

I agree, the easiest way to find out if your are full is to watch for return from the overflow. I normally do not fill my tank if I am going from campground to campground. I will carry about 5 gal. My thought is water=weight and that uses more gas