Dye test

PoolFrog

Well-known member
Aug 9, 2013
99
Dallas, TX
I have determined that I have a leak based on the bucket test. I went around doing the dye test today with the pump off, putting dye in and around all of the returns, both skimmers (putting the syringe into both holes at the bottom), the light niche, and any cracks that I saw in the plaster. I wasn't able to find anything.

To test the returns, was I supposed to remove the eyeballs?

Have I done this test correctly? What should I try next?
 

PoolFrog

Well-known member
Aug 9, 2013
99
Dallas, TX
Yes, I've read that article, but it doesn't get into the specifics of doing the dye test on parts of the pool like returns, skimmers and light niches. I'm wondering if there is a certain technique to it, because I wasn't seeing the dye being pulled toward anything that I checked today.
 

ajw22

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Jul 21, 2013
9,754
Northern NJ
No special technique to using dye. The dye lets you see the water flow. Squirt a bit of dye and observe the way it flows.

If you see anything you can gently squirt a little food coloring in the area and see if it gets drawn into the place you think may be the leak ‘ the water should be calm, don’t stir up the water while squirting, you are looking to see a tendril of the color being drawn into the leak
 

ajw22

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Jul 21, 2013
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Northern NJ
If I'm not seeing dye getting pulled into a return, is there any reason to plug it?
Dye will not get pulled into a return with the pump running. Are you doing the dye check with the pump on or off?

Dye will show you a leak around the outside of the return.

Plugging a return lets you determine if the leak is from the pipe leading up to the pool wall.

You need to take a structured approach using a process of elimination to find a leak.
 

PoolFrog

Well-known member
Aug 9, 2013
99
Dallas, TX
I did the dye test with the pump off. So a leaking return line won't pull the dye inward?

I agree, process of elimination is the way to find the leak. I'm just trying to figure out what to try next.
 

duraleigh

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Using dye to locate a leak is incredibly delicate. The slightest disturbance of the water makes it impossible to see the source of the leak. How much water are you losing daily?
 

Jimrahbe

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Jul 7, 2014
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Bedford, TX
pf,

Just for reference, I am in the DFW area and lose about 1/8th inch a day...

I agree with Dave, unless you have a huge leak, and are within a inch or less, you will not see much dye movement.

In my opinion, the best way to find a leak is to first determine if the leak is more or less with the pump running.. If the leak is more with the pump running you know you have a pressure side leak. If it is not more with the pump running, then the best bet is to let the water keep dropping until it stops..

Most gunite pools leak at the Skimmer, or at the Light...

What I do is use a paint stir stick and stick it over the coping and down to the bottom of the skimmer mouth. When I pull the stick out it has a water line that I mark with a pencil.. I do this for several days in a row and it gives me a pretty accurate record of just how much water is lost each day..

Thanks,

Jim R.
 

PoolFrog

Well-known member
Aug 9, 2013
99
Dallas, TX
Thank you for your suggestion. I will leave the pump off again tomorrow and take morning and evening measurements to see how much water was lost during the day so I'll have a number to compare against last week's loss when the pump was running during the day.
 

duraleigh

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I especially like JimRahbe's method of measuring the water......very simple and very accurate. Report your results back from today's test and we'll all help you find the leak.
 

jimmythegreek

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Aug 10, 2017
1,254
Morris Cnty NJ
Depending on your equipment setup and valves you can sometimes isolate sections of the pressure side. Usually tiny leaks are returns if theres no air bubbles. If you can isolate some returns you can check water level while closing sections off and narrow it down somewhat
 

PoolFrog

Well-known member
Aug 9, 2013
99
Dallas, TX
The rain turned out to be a light sprinkle that only lasted a short time, so I don't think it affected the water level much at all. I measured this evening after leaving the pump off all day, and it appears that the amount of water loss is about the same as it was on days when the pump had been running.

Does this rule anything out as a possibility, or indicate something to focus on?
 

Jimrahbe

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Jul 7, 2014
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Bedford, TX
pf,

In my mind, it rules out any of the pressure lines.. If a pressure pipe had a leak, you would think it would leak more when under pressure than when not under pressure.

That said, I would want several days of data and not just one day, but that is me...

It does not rule out water leaking around the outside of a return pipe, through the gunite, but I doubt that will be your problem.

If this were my pool I would want to eliminate the skimmer and the light before going crazy..

Did you take the light out of the niche and do the dye test where the wires come in the back of the niche??

Thanks,

Jim R.
 

PoolFrog

Well-known member
Aug 9, 2013
99
Dallas, TX
No, I didn't, so it sounds like I should. I only shot dye around the outer ring, and now I'm thinking that I need to go back and make sure that I sufficiently covered the entire perimeter of it. Could that be a leak point as well as the inside?
 

Jimrahbe

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Jul 7, 2014
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Bedford, TX
pf,

Most light leaks are not around the outside of the niche, so you can't really see it by squirting dye around the ring. Most lights leak around the back of the niche where the electrical wires come in...

It will be chilly to find that now... :)

Jim R.
 

PoolFrog

Well-known member
Aug 9, 2013
99
Dallas, TX
Yes, I was trying to work fast yesterday when I was in the water doing the dye test. It sounds like I'll be taking another cold dip in the pool to do further testing, but that's ok - especially if I successfully find the leak!

I've never opened the light before. Since the pump has to be off for dye testing anyway, should I shut off the circuit breaker before I pull the light out? To be honest, I'm sort of intimidated by working with electric components under water!
 

Jimrahbe

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Jul 7, 2014
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Bedford, TX
pf,

It is perfectly safe, but like you I'd want to be cautious anyway and I'd pop the light breaker..

I would not want to be in the pool with the storms we are having this morning... :mrgreen:

Jim R.