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

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.

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!

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.

The unit worked exactly as described. It allows me to add water to the fresh water tank and know how much I added. That is handy when I want just enough water for a night or two of boon docking while traveling without filling the full tank. When I finished using it, the display stayed on no matter what I did. Some said it goes off in a short time after no reading. Mine finally went off sometime during the night. I am thinking it will be O.K. as the display is LED--can't be using much current. It is plastic but seems well made for what it is. Just don't jerk on the hose when it is hooked up.

We use these in my pest control company to know how many gallons of water we are putting in our truck tanks every day. We have to be correct in order to know how much chemicals to mix in. I've tested in many times as well for accuracy and its pretty spot on. We use these every day and it will last for about a year. The screw in connections are plastic and typically over time the connection just gets bad. You have to store it inside when not being used. We just leave it permanently connected and leave the end of the hose inside the warehouse. If you leave it outside it will have water leak in and ruin it. However, considering what you pay its well worth it for us. Update: The quality has gone down since I started using these. They leak water from a part that is not a hose connection. I asked for a replacement since one I just ordered leaked and the replacement leaked in same exact area.

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.

Works great, accurate but will break the hose connector off if you pull on it with the hose, the second one I bought I connected between a hose real and the house so that does not happen again. I have a well that does not handle a lot of water usage at a single time this works great to maintain my water level in the well without running out

This water meter seems to do a good job measure water quantity when running water through hose full rate. It is not accurate if you want to measure slow water rate. I place the meter on the end of my hose, opened the water valve fully, and fed the water into a 3 gallon bucket. When the meter read 3 gallons, the bucket was appropriately full. I then restricted the water flow to a much lower flow rate. When the bucket was full, the meter only showed about 1.5 gallons. I want to measure the water at a slow flow rate, so this meter isn't going to help me, but if your application allows water to flow at a full rate, it is probably good enough for you. The device is made of plastic. It is reasonably sturdy, but if you place it between your water spigot and a hose, and then start pulling on the hose, I predict it will break. It should not be stressed. December 2021 Update: After two years of use...I would say light use...my water meter failed to display water usage. Initially I thought it needed a new battery, but a new battery didn't help. I estimate that about 1000 gallons of water passed through the meter. While disappointed that my meter failed, I will probably buy another one and hope it lasts at least two years. When adding water to my boat and RV fresh water tanks, I like to have some idea how much water is put in the tanks. This is more important on my boat because it has no gauge for 170 gallon fresh water tank, so it is helpful to know how much I have used since last fill. A meter makes things easy. Without a meter, I have time how long it takes to fill a 5 gallon bucket and then time how long it takes to fill the tank.

I have only used the meter once so far and it worked nicely.

Excelente articulo.

Very happy

Works great after a few month of use. Keeps a record of total gallon count and current usage gallon count(2 readings).

Practico y muy eficiente, lo recomiendo.