theory vs practice - filling a pool

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3/4 hose will only deliver that volume if pipe and valves going to it are 3/4" full flow. I filled my 15,000 gallon pool recently with 3 hoses. One 3/4" and one 5/8" hose connected to regular outdoor taps. One 3/4" lawn irrigation line I connected directly to the house mail water supply line. The irrigation hose delivered more than the other 3 combined. I started the first two at 3 p.m. and the irrigation line at 8 p.m. I got up at 3 a.m. and shut the irrigation line off (afraid it would over fill) by 8 a.m. the pool was full. YMMV
 
I do have an irrigation line 15 feet from the pool. I cut and capped it off for the excavation. My thoughts were to put a hose bib end on it to use it to fill. It gets way higher flow than my outdoor spigots.
 
Brianf60 said:
The irrigation hose delivered more than the other 3 combined. I started the first two at 3 p.m. and the irrigation line at 8 p.m. I got up at 3 a.m. and shut the irrigation line off (afraid it would over fill) by 8 a.m. the pool was full. YMMV
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Genius! - You just told me how to fill my pool when it is ready!! I have a 1" irrigation line (on city water) I had to cut and cap where the pool will be built. I'm going to make a 1" fill line from that!
 
sehrmude said:
Genius! - You just told me how to fill my pool when it is ready!! I have a 1" irrigation line (on city water) I had to cut and cap where the pool will be built. I'm going to make a 1" fill line from that!
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I have also been investigating this. 1" hoses are ridiculously priced. But, 1" Sch 40 PVC is like $3.50 for a 10 foot section. For me, I plan on plumbing from my capped irrigation main-line all hard PVC to my deep end since I only need like 15 feet and letting it rip. I'll turn it on and off from inside my house at my master irrigation ball valve. Once done, I'll just cut it all off and recap it.
 
PoolGate said:
I do have an irrigation line 15 feet from the pool. I cut and capped it off for the excavation. My thoughts were to put a hose bib end on it to use it to fill. It gets way higher flow than my outdoor spigots.
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Just be careful almost all hose bibs have a large restriction. I got a plastic adapter to fit the irrigation line to a garden hose that I used to water my law before I had the lines connected to the house. About $5
 
OK - I just told a friend about this - he JUST had his pool refinished. He said: "New finish on pool will not tolerate high volume and 'they' had to slowly fill his pool to not damage the new finish. How would you diffuse the high pressure so you don't damage the finish?
 

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sehrmude said:
OK - I just told a friend about this - he JUST had his pool refinished. He said: "New finish on pool will not tolerate high volume and 'they' had to slowly fill his pool to not damage the new finish. How would you diffuse the high pressure so you don't damage the finish?
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You could lay the hose/pipe on the edge of the deck and shoot it out long ways over the pool area. This would disperse it without directing it at the walls. You also could fill the pool partially and once you have some water, then add the higher capacity hose/pipe.
 
OK - I just got a pressure gauge for a hose. I measure 62psi for my outdoor faucet right at the faucet. If I put the gauge on the end of a 75ft hose, I still get 62psi. I measured on my laundry sink and also 62psi. Not sure how to use it as I show no pressure drop. Any advice?
 
Put on the Y splitter that mas985 posted (post #17), add a hose to one side and the pressure gauge to the other side and then open up the spigot with the hose end running full bore. The pressure gauge will read your open faucet pressure. The hose end can be assumed to be 0 psi
 
But put the splitter on the spigot. If you want to use head loss equations, you must measure the pressure at the hose attachment point WHILE the flow rate is going through the hose. The static pressure is irrelevant.
 
mas985 said:
But put the splitter on the spigot. If you want to use head loss equations, you must measure the pressure at the hose attachment point WHILE the flow rate is going through the hose. The static pressure is irrelevant.
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ok - I have one of those exact splitters. So I put the pressure gauge on one side and the 75 foot hose on the other and got 18psi. Still not sure what this means since if I put a shorter hose I would have gotten a lower psi but I know the volume would have been higher. When I took the hose off, for instance, I got 0 psi and all the water went out the open side. Still confused! ;)
 
What you are measuring is the head loss through the hose. A shorter hose will have less head loss (for a given flow rate) or lower pressure loss. So if you plug these numbers into the web site (assuming they are doing the calculation correctly), you should get a higher flow rate out of the shorter hose with the lower pressure.

As a rough approximation, head loss in a pipe can be expressed as the following:

Head loss (ft) = Constant * Pipe Length / Diameter^5 * GPM^2

So even if you measure lower pressure (i.e. head loss), it can and is offset more by the length of the pipe so GPM is higher.

I just realized that site doesn't allow for variable pressure. But you can use this formula for a rough approximation

[CORRECTION]

Pressure loss (PSI) =3.32e-4 * Pipe Length / Diameter^5 * GPM^2

So for a 18 PSI pressure loss in a 75' hose, GPM is 13 GPM +-
 
mas985 said:
What you are measuring is the head loss through the hose. A shorter hose will have less head loss (for a given flow rate) or lower pressure loss. So if you plug these numbers into the web site (assuming they are doing the calculation correctly), you should get a higher flow rate out of the shorter hose with the lower pressure.

As a rough approximation, head loss in a pipe can be expressed as the following:

Head loss (ft) = Constant * Pipe Length / Diameter^5 * GPM^2

So even if you measure lower pressure (i.e. head loss), it can and is offset more by the length of the pipe so GPM is higher.

I just realized that site doesn't allow for variable pressure. But you can use this formula for a rough approximation

[CORRECTION]

Pressure loss (PSI) =3.32e-4 * Pipe Length / Diameter^5 * GPM^2

So for a 18 PSI pressure loss in a 75' hose, GPM is 13 GPM +-
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Thanks!

This looks good but would the pressure loss be the original 62psi - 18psi or 44psi loss. No?

I think the previous advice just to time filling a 5 gallon bucket is going to be most accurate. Or I could just get a flow meter.
 
The pressure that you use is the pressure loss measured when the water is flowing through the hose so 18 PSI. 62 PSI has no relevance because no water is flowing.
 

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