Rainwave RW-9FM Digital Water Meter - Accurate Water Usage Measurement - Helps Conserve Water and Costs

This water meter is very well designed and very useful. It turns itself off when not in use and turns on when it detects running water and stores both the new water flow amount and another number is the cumulative amount when you start and stop putting water through it. Perfect design! I have two of these - one for fresh water and the other for black tank flush and fill. With RVs and campers you don't want to carry extra water because its heavy! So I need this to partially fill the fresh water tank for use while driving until the next stop. A black tanks best friend is water which should always be in the black tank to keep everything from drying into a solid and not flushing. The rule of thumb is to always have at least 10% of the tank capacity in the black tank although I vote for 15%. So at the end of a flush and departing a campground I make sure I have water in my black tank to slosh around while in motion and in storage. The only way to measure this without running through your camper with a water bucket or keeping your foot on the toilet flush pedal is to use this flow meter. Of course if you double flush your black tank when you depart a campground this is also indispensable. Very handy!

The name of this product is flow meter and I suppose there is some confusion on that term. I was looking at "flow meters" that cost a lot more money and figured I didn't want to spent that much since I'm not an irrigation professional. The price on this unit was so low that I figured there has to be a difference between the "flow meters" I was looking at and this product. So, here is the difference.Flow meters that I was looking at provide a direct reading of gallons per minute flowing through the meter. This product simply gives you the number of gallons (or liters) that have flowed through the meter since the reset button was pressed or the flow started. There are two reset buttons so you can made two different cumulative measurements. But, to get gallons per minute, which is the goal for irrigation calculations, you just need to add a stopwatch. In my case, I ran the water, hit the reset button and started the stop watch and ran the water for five minutes. That time period allowed my well pump to cycle a couple of times so I got an accurate measure of the flow over the pressure cycle of the system. Now, do the math and you get gallon per minute. In my case, I got 5.9 gallons per minute, which is more or less what I expected and now I can do my irrigation design based on that. Simple.For the price, this was a perfect solution for me and I recommend it. The true "flow meters" i was looking at ran around $100 and require a little knowledge to use correctly. Along with my wrist watch, this unit was a breeze and gave me the information I needed at a bargain price. For the do it yourself-er, this is the simple answer.

This is my first review of the product I posted:Purchased to monitor water usage in my RV. I first tested by filling a bucket and found it to be fairly accurate. A few weeks later I used it on the RV and it was perfect. A couple of more weeks pass by and I go to use it again on the RV and it just shows 0.0 on the screen. As my "return" window has passed, I started to fiddle with it and found the impeller to be jammed. Curiosity got the better of me so I pulled this thing apart. It must have been a manufacturing defect because honestly, while it "feels" kinda flimsy... it's really well built, sturdy, and essentially a sealed unit.Update:I purchased the replacement and made sure I used it enough during the return window. As I suspected above, I must have just gotten a faulty first one. It's been working flawlessly. It's not lab/industrial accurate, but it's close enough for use on an RV. The storage tank gauges, especially on older RV's are pretty much useless. WIth this hooked up on the inlet, I know over a long weekend when it's getting close to time to dump. A great gadget for the money.

Now that I know of these flow meters and have one, I think this is a "must have" for RV use!!I had read a post by a RVer about using this exact model Flow Meter. I thought what a great idea! Using this meter puts an end to the "go inside and check the lights and see how much water is in the tank while I fill it up".I know my fresh tank is 49 gallons but I don't want to travel with a full tank if we don't have to. So with this, I can, and did, put just 20 gallons in the tank, and I know I did with this device.I did check it by filling gallon water jugs and this is pretty accurate. I used it by attaching the device to my water intake and then to our fresh water hose to the spigot. It worked perfectly and I stopped the water at 20 gallons. With another hose, I also used this to put 8 gallons of water in the black tank to treat it before our short trip. Sooooo much easier!You get the device, mine had batteries pre-installed, and the display can be either gallons or liters. It auto shuts off after several minutes of non-use.The device is small and as it should be, waterproof for the electrics.For the very nominal cost, and for what it does, if you want better control of things like water weight for things like overloading and use for boondocking, this Digital Water Flow Meter is a must-have.