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Take The Mystery Out Of Filling Your Tanks

Preparing for a road trip is always fun. Not only do you have the expectation of adventure and lure of the open road, but there’s the satisfaction of getting your food stores in order and prepping your RV for the trip. 

Though we have always kept a case of water bottles on board, more and more we are relying on our fresh water tank for our water source. Whether we are at home or in a campground, we filter the incoming water with a Clear2O® filter first.

That water is fed into our fresh water tank which we sanitize frequently. All fresh water then goes through the onboard filtration system, and finally, any water we drink goes through the water filter in the residential refrigerator

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The problem

We always travel with a full tank of water. The biggest challenge when filling the fresh water tank is knowing exactly when it’s full. I typically implore the “listen and run” method. After securing the proper water hose, the external filter, and the water pressure regulator, I turn on the faucet. Now it’s time to listen for the water to overflow my fresh water tank and start pouring out of the overflow tube on the other side of the coach. 

Watching the gauge in the coach is pointless. Even though mine are fairly accurate, the 33% and 66% readings don’t really help me. Filling up 90 gallons can take a while, and inevitably I get distracted and start working on something else. Once I hear the water running out of the overflow, I run to the faucet to turn it off. 

There are a few problems with this method. The first of course is that I do tend to get distracted and can’t always shut it off in a reasonable amount of time. Second, though the water running out on my concrete RV pad poses no real issue, it is still a waste of water.

Worse, when I’m at an RV park or campground that water is typically running out on grass or even dirt, creating a muddy mess on the side of the coach where we hope to relax later. 

This concern is magnified when filling a black tank in preparation for flushing. Overflowing your blank tank can be a messy disaster inside and outside the coach. Knowing how much water you are allowing in during the black tank flush is a huge benefit.

Too often we don’t get enough water in the black tank to flush properly because we are simply too afraid of overflowing it. Level gauges in black tanks can be notoriously suspect as the sensors get covered in debris. After a successful black tank flush, you also want to put a few gallons of fresh water back in. How do you figure out how much a “few gallons” is? 

The solution? Use a digital water flow meter

There is a simple device that will accurately track that water flow for RVers. The Rainwave RW-9FM LCD Digital Water Flow Meter will display on a digital LCD screen in gallons or liters exactly how much water has flowed past its sensor. Powered by a 3-volt button cell battery protected from moisture with an O-ring, the device automatically starts tracking usage as soon as water starts flowing through it. 

water flow
The Rainwave digital water flow meter ($20, Amazon)

Not only can you use it as already described, but it’s also a great way to determine the capacity of various tanks and containers, like the fresh water tank capacity for that older RV you haven’t been able to find information or a manual for.

This type of device is also fantastic for accurately mixing water with concentrates. Cleaning formulas, concrete and grout mixes, and plant food concentrates all benefit from accurate portions of water and concentrate. 

I would opt to install it after the pressure regulator to protect the device even more from high-pressure water lines. With a digital water flow meter, I can finally abandon the listen & run technique. Next time, we’ll discuss the open & pray technique of flushing the black tank. 

The Rainwave RW-9FM LCD Digital Water Flow Meter is available on Amazon for about $20.



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