[QUOTE=chalsall;442258] And syphoning wasn't possible because air was always ready to break the syphon. (Importantly, the source of air is completely underground, and can't be accessed by mosquitoes.)

[/QUOTE]
Addition of a short upward turn in the inner end of the tube should prevent the air from going inside the tube and breaking the siphon.

[QUOTE=a1call;442260]Addition of a short upward turn in the inner end of the tube should prevent the air from going inside the tube and breaking the siphon.[/QUOTE]

You misunderstand...

The breaking of the siphon was desired and by design.

We want the tanks to overflow sanely, but not drain below what they can hold.

Yes I did not understand, but regardless my upward comment was in regards to addition of new flexible tubing as shown in the image and not in regards to the existing relief system.
If there is a chance of air entering the flexible tubing perhaps if the drain valve is just under it (not likely), then adding a short upward turn would prevent the air from entering the [U]proposed[/U] flexible tubing.

[QUOTE=a1call;442268]Yes I did not understand, but regardless my upward comment was in regards to addition of new flexible tubing as shown in the image and not in regards to the existing relief system.[/QUOTE]

Fair enough.

So you know, that "flexible tubing" in the image is 1/2" vinyl hose in an independent "S" path used to measure levels.

One end is anchored at the bottom of the tank, then it goes out of the top of the tank, circles back down to the bottom of the tank, and then back up to the top of the tank.

The red liquid you see at the top of the tube is Chinese chill oil. Environmentally friendly (and tasty!).

The green electrical tape you see in that image is where I took a physical measurement.

The Chinese Chill oil is present in the vinyl tubing and not in the actual tank. Is that correct?

[QUOTE=a1call;442272]The Chinese Chill oil is present in the vinyl tubing and not in the actual tank. Is that correct?[/QUOTE]

That is correct.

Chinese Chill oil is red and is lighter than water. It is used as an indicator in a narrow column. About 4 cc was used in this particular case.

Given that the density of the indicator oil is less than that of the water, it is logical to expect the actual height of the [U]water[/U] inside the tank is neither at the top nor at the bottom height of the red column, but somewhere in between, near the bottom of the red column.:smile:

[QUOTE=a1call;442274]Given that the density of the indicator oil is less than that of the water, it is logical to expect the actual height of the [U]water[/U] inside the tank is neither at the top nor at the bottom height of the red column, but somewhere in between, near the bottom of the red column.:smile:[/QUOTE]

I fart in your general direction.

You are, of course, correct. There is always a margin of experimental measurement error.

It's an idiot who doesn't take this into consideration, and then carry on with their work.

[url]https://www.wunderground.com/hurricane/atlantic/2016/Tropical-Depression-Twelve[/url]

Hey, Chris,
When I first saw the track of this storm it looked like it was aimed right at you. However, the models all have it turning more to the North. You might still get a lot of rain. If that happens, I hope it does not put you in another overflow situation.

[QUOTE=kladner;442665]When I first saw the track of this storm it looked like it was aimed right at you. However, the models all have it turning more to the North. You might still get a lot of rain. If that happens, I hope it does not put you in another overflow situation.[/QUOTE]

LOL... Yes, thank you. I have multiple views of WU open at all times in a browser on one of my screens, and check them regularly.

And, yeah... I've been gravity feeding the water from our 3# 1,000 gallon tanks over to our neighbour's (same architect) 6,000 tank. His overflow is sane; and for every 1mm of rain we get the three tanks raise by 1cm. We should be able to handle 10cm of rain before anything heavy hits us.

Ah, the joys of being a home owner in the tropics.... :smile:

Some shit going down in my town. At least two separate shootings, another large fight, the 1st was on the local campus, I walked right by about ten minutes before it happened, and the 2nd was reported by me to 911. Sad night.

And some idiots about two hours later set off fireworks on campus, spawning another wave of panic

[url]https://twitter.com/MasakiSugimoto/status/779954974511857664[/url]