Anyone use or install a Flume2 water monitor

jwiegley said:

Another reason I continue to worry about a possible leak is that my CH and CYA keep dropping. They don't drop fast, but they aren't anywhere NEAR as stable as my reading would indicate. I've been having trouble keeping CH above 300, and so far I've added 70 pounds of Calcium Chloride in the past three months.

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this indicates a leak.

Even if your source water had zero CH, CH would never decrease with evap and fill. CYA is also only found in pool water and if it is decreasing more than a few ppm per month (unless you experience insane heat and UV like we do here in the desert), then that also indicates pool water moving out of the pool and fresh water added to the pool.

70lbs of CH increaser in your pool is over 300ppm CH (more or less). 300ppm in 3 months is a leak. Western pools rarely, if ever, need CH as our water is very hard.

jwiegley said:

I wouldn't say I'm convinced.

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When you're talking about 1/4" = 150 gallons, then yah, you need more accuracy than fingers. Maybe even a couple buckets, one at each end of your pool, to help rule out what might be affecting the evaporation in the bucket (wind, shade, etc).

For all you know, X% might be evaporation, and the other Y% is a leak. If X and Y are < 1/4", that's pretty hard to eyeball. On a still morning I can see 1/16 inch increments on my ruler.

I would make sure the bucket is as low in the water as possible. At those measurements, even heat on the exposed part of the bucket could throw off the numbers. I would expect a light-colored plastic bucket would be best. If you go with two, they should be identical.

Ugh. I hate when they paint over everything. Can you a few more shots at different angles and then point to the pipe that you think goes to your autofill.

It looks like you have an irrigation valve in there too. So is this part of the irrigation system also??

If I've identified the pool's autofill shutoff valve correctly, that's an anti-siphon valve, which is better than nothing, but not the kind of backflow preventer that should be there. The valve you have is intended to be used for things like a sprinkler system, where once the valve is closed, the pressure on the output side is relieved by draining out through the sprinklers. Even with the valve open, the pressure is reduced, because water is flowing out through the sprinklers.

When you have a pool autofill valve on the output side of an anti-siphon valve, whether the shut-off valve is open or closed, there is constant pressure on the anti-siphon component of the shutoff valve, because the auto-fill valve is closed (most of the time). That side of the shutoff valve is never relieved of pressure. And if this manifold of valves is plumbed like most are, it's getting its water from the street-side of your home's pressure regulator, which means the pressure on that anti-siphon component is full-on (and probably high). The anti-siphon mechanism of that shutoff valve is not rated for 24/7 pressure like that. It will fail, if it hasn't already, and while the valve will still function as a valve, the anti-siphon safety measure will no longer work. And you won't know if it's working or not, because there is no way to test it.

The valve I linked at Amazon is a true backflow preventer, rated for full pressure on both sides of it. And it has test ports that can be used to confirm it is working correctly. When you're inspired, you should correct that plumbing. I can't imagine any of this has anything to do with your leak investigation, just an FYI.

jwiegley said:

- I lowered the pool's level a bit, so there is more head-room between the auto-fill's target level and the outflow pipe.

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The level of the pool should be determined by the skimmer opening (more than anything else), and not what solves an auto-fill issue. So let's start there. While the water level can vary a bit, the ideal level is halfway up the skimmer opening. If you're there, then you're golden. If not, then you might consider adjusting the overflow pipe, not the pool's level.

Can you describe your "outflow pipe?" Is it a vertical pipe in the auto-fill well? If so, then what you have is more accurately called an auto-leveling system (not just auto-fill). Assuming that's what you have, both the pool level and the overflow threshold are adjustable. I take it you know how to adjust the auto-fill level. You adjust the overflow threshold by shortening or lengthening the overflow pipe. You can do this in several ways. The simplest way is to pull out the pipe (it is likely just friction fit into a fitting at the bottom of the well). It should just wiggle free. GENTLY! You do NOT want to compromise the fitting at the bottom of the well. If it doesn't come free easily, don't mess with it.

If it does come free, you would replace it with a slightly longer pipe. It should be a standard size of PVC. You would, of course, already have this new pipe on hand. You pull out the old one, cut the new one to length, and wiggle in the new one. Keep in mind the pool will be draining once you pull the old pipe out, so be ready with the new one and work quickly.

A simpler method, which you would use if the old one doesn't wiggle free, is to just slide a PVC coupler over the existing pipe. The only problem with this MO is that it won't be a granular adjustment. It'll add about an inch to the overflow threshold, and not very adjustable. If you go this route, and find the coupler adds too much height to the overflow pipe, then use a hack saw to cut the coupler. In this way, you can add just about any length to the existing pipe.

If this doesn't sound like what you have, then "never mind." Or if your water level is currently acceptable, or you just want to leave well enough alone (always a good way to go), then consider it solved.

All that said, it doesn't really explain where all the water was going, how it was leaving the pool. Unless what you've discovered was that, for whatever reason, your auto-fill valve was just pumping water into your overflow pipe, and sending all that water into your garden (or wherever it exits).

I've had that problem before myself. I took precautions against that happening again (at least happening without me knowing about it). I exposed and extended the end of the overflow pipe (it was buried in brush in the garden), and I can now see it, to keep an eye on it. And then I configured a cam so that I could watch it whenever, from wherever. If I see water coming out of that end of the pipe during a rain, then that's expected. Otherwise, if I see it draining when it shouldn't be, I can assume my auto-leveling system is malfunctioning in some way.





I couldn't quite get the angle on the end of the pipe with my cam, so I solved that with a small mirror. The second pic is a still from my pool cam, which is PTZ, so I can check on several aspects of my pool, remotely. This can be seen as extravagant, sure, but it's peace of mind while I'm away, which is often these days.

The pic I posted previously, of my water level ruler, is also a still from my pool cam. I mounted that ruler permanently (which got a few snickers here on the forum), and it is pretty goofy, but I use it almost every day. I can monitor my pool's water level to 1/16 of an inch, from anywhere on the planet. I can hop back and forth between my cam's "Level" and "Overflow" presets, and verify all is well with my auto-leveler.

A story for another day: I have a motorized valve, that is scheduled by my pool automation system, that is inline with my auto-fill valve supply. It's for a purpose other than what we're talking about here, but I can use it to shut down my auto-fill valve remotely if I have to (like if I spotted my overflow pipe draining water in the middle of summer, while I was away).

The autofill setup still doesn’t explain the chemical discrepancies and so I’m still not convinced you don’t have a leak. If the auto fill was just pushing water out the drain pipe because the levels aren’t correct, that wouldn’t have any impact on the CH and CYA. 70lbs of calcium increased in under 3 months is a huge change in CH.

You said you took the spa out of the equations … well, is your spa leaking somewhere? You may need the leak detection company, or a smart plumber, pressure test the return side of your pool plumbing. That will require a lot of cutting and manifolding the various PVC pipes since they’ll all be interconnected at the spa with the air lines. You may have a leak somewhere in the returns and the water loss is going into the ground where you can’t see it easily.

^^^^ @JoyfulNoise sounds as unconvinced as I am, just using different clues.

Here's a troubleshooting step you could take, before you modify your outflow pipe. Put the levels back where they were, and locate the exit of the outflow pipe. Then observe it. If you can see 150 gallons a day running from it, then you're on to something. But if it stays dry, then your water loss has nothing to do with your auto-leveling system. And if you've ruled out evaporation (I think you said you did), then it's gotta be a leak.

By the way, dropping your water level to stop a leak might be a clue as to where the leak is. If all you did was drop the water level lower than the crack/hole, then you're making the wrong assumptions about the spa and the auto-leveler. This MO is sometimes used in desperation when a leak cannot otherwise be detected. Just let the pool leak out until it stops losing water. Somewhere at the level of the water is the leak. It can still be underground from a pipe, so this trick doesn't tell you if it's a plumbing or plaster leak, only in which dimensional plane to start looking.

Also, keep in mind, that, while unlikely, you might have more than one leak, which really complicates troubleshooting. This might be something to think about if your data keeps contradicting itself. The steps for that then involve isolation. One such isolation step is what @JoyfulNoise suggests, a pressure test on the return plumbing. That would either discover or eliminate a leak in the underground plumbing. It found, that wouldn't necessarily mean that is your only leak. It just means that if not found it isn't in the underground plumbing.

Another step is to isolate the auto-leveler. You started to do that, but neglected the overflow pipe. To fully isolate the system, you'd shut off the auto-fill valve source, and confirm its shutoff valve is NOT leaking, and also cap off the overflow pipe.

Assuming you've done so correctly, you've already isolated the spa. So that's the big three.

I think if you did all of those isolations, and then filled the pool to normal level, and it still dropped more than could be accounted for by evaporation (by using the bucket test), then you've got a leak in your pool's plaster somewhere. If you then drop the water an inch or two, and the water loss stops (with the plumbing and auto-leveler and spa still in isolation), then you know about where the leak is: somewhere in your edge tile just above the water level.

If none of that points to a leak, then you isolate the pool, and "un-isolate" one of the other three, until you get the water loss again. This is just basic troubleshooting. You isolate all but one thing, and see if the problem persists. If not, you isolate all but the next thing, etc.

But you have to be methodical, and thorough, when you isolate, otherwise you'll get false data. If you get failure in more than one isolation pass, then you have more than one problem (in your case, more than one leak). But at least you'd know which two systems are leaking.



Sidebar: looking at the pic of your skimmer opening reminds me of why I use rulers for determining water level. Refraction makes determining where the level is, relative to the skimmer opening, really deceptive. It's not where you think it is. Unless you measure the water level somehow, relative to the skimmer, you cannot trust your eyes. I affixed my water level ruler such that zero is the bottom of my skimmer opening. That way, whatever the ruler reads is the amount of inches of water above the bottom of the skimmer mouth. Which is the main thing I want to track. I don't have a main drain, so if the water gets to "ruler zero" or below, I'm going to fry my pump.

PS. Those "toilet bowl" auto-fill valves are barely reliable when new and clean. As a matter of preventative maintenance (regardless of the status of your water loss mystery), scrub that well and clean out all that dirt from the well and around that rim. Yikes.

The second of my auto-leveler failures was due to tiny rocks getting into the valve (from the city water and/or from me working on the pipes upstream). That black top piece pops off to reveal a screen filter. Check that regularly for debris, grit and gunk. Keep that clean. Since connecting my auto-fill valve to my whole-house water filter and water softener combo, it's worked so much better. The first auto-leveler failure was due to calcium deposits forming inside the valve. The softener all but eliminated the calcium problem, the whole-house filter takes care of the grit. But I still check under there annually.

If your auto-fill source water is direct "from the street," you'll have to be extra vigilant. Or you can install an inline filter, perhaps when you get the backflow preventer installed. I've used this one in my irrigation system (protecting my drip emitters), with great success so far. They have a handy clean-out system, which makes maintaining them a snap.


If you have your plumber put it in the right place, it would protect both your auto-fill valve and your drip system. Your drip system already has a filter on it (have you ever checked it or cleaned it out?). But if it's just as easy to install this second one to work on the drip, too, then why not?

BTW, the new backflow preventer should be installed to feed the auto-fill valve and the drip valve and that hose bib. Your drip system and hose bib each have their own BFP, or sorts, but again, since the plumbing is getting reconfigured right there anyway, might as well get a little extra value out of that expensive new BFP.

Ha, and you thought all there was to owning a pool was swimming in it!

PPS. If you want to try and approach my level of crazy, you could install a water meter along with everything else! I have one on my pool and one on my drip system. I can watch my dollars flow more easily that way. I use these:

But I guess your Flume handles that.

Sorry, couldn't resist, mostly because I just finished chewing myself out for this only yesterday, which I spent cleaning gutters that looked a lot like this. If you've got weeds growing in the dirt you've neglected to keep from collecting, uh, you've let it go too long!! My weeds were so tall you could see them from the ground, grown higher than the top of the gutters!

Maybe I should put my tomatoes up there, 'cause they sure won't grow for u-no-what in the planter I built!