Diagnosing Possible Leak

ofcdduke

Active member
Apr 22, 2020
26
Metairie, LA
I am now taking care of my MIL's pool. I recently replaced the main pump due to it leaking. As I'm trying to get the water chemistry in line (pool has been neglected), I am trying to map out the plumbing and find what might be a leak. I have identified the drains- two skimmers and a main drain. However, there is a 4th pipe plumbed in with the drains that I have no idea where it goes. The 4th line is 3/4" with a ball valve. The line is in the red box:
pool.jpeg
Any idea what that could be? I know that if all the drains are open, the water level in the pump drops and the pump will not prime. Not sure if the leak is in the drain or the skimmer yet, but I know that if the 3/4" line is open, the water level drops in even if all three drains are closed. If I run the hose directly into the pump basket, the pump does not over flow except when I have one skimmer open and everything else closed. If I start the pump with one skimmer open, the pump works fine. If I then open the other two drains, the pump continues to work fine. But it the pump is turned off, it will not reprime and start again. Just trying to get a handle on the basic layout before I call a pool company to come look at it.
 
I am taking care of my MIL's pool that has been neglected for some time. There was supposedly a "pool guy" taking care of it but I couldn't tell if he was doing anything or not.

After cleaning all the debris out and emptying the skimmer and pump baskets, I tested the water. This is what the first test results were. All these tests were done within a 5 day period:

Test 1:
FC- 0
CC- 5ppm
Alk- 500ppm
Cal Hardness- 500ppm
pH- 7.5
Pool Shock added.

Test 2
FC- 5ppm
CC- 0ppm
ALK- 110ppm
Cal Hardness- 350ppm
pH- 7.5

Test 3
FC- 6+
CC- 0
ALK-300ppm
Cal hardness- 380ppm
pH- 7.5

The Taylor treat page said to not add chlorine and let the levels come down. However, I also need to lower the ALK. What would some suggestions be to get the chemistry right? FYI- the pool has a sand filter thats pretty new. I plan to backwash today because I don't know when it was last done. The pressure of the filter is just under 15. I fugured it couldn't hurt to do it so I can have an acurate record of the maintenance.

Any suggestions would be appreciated.
 
What test kit are you using?

You need to know CYA to set the correct FC level.

What chemicals did you add over the 5 days and when?

Why are tests like TA all over the map?

What is the pH, TA, and CH of the fill water?
 
Using a Taylor K-105 DPD test kit. Only thing I added was pool shock after the first test. The pump has been running 24 hrs a day. I am going back this afternoon to test again. I can't test the CYA because the test tube that was supposed to be in the kit was not there. Is there a way to test CYA without the test tube? I will test the tap water from the hose today.
 
Using a Taylor K-105 DPD test kit.

You mean the K-1005 Test Kit?


That test kit lacks the FAS/DPD chlorine test to accurately test FC over 5PPM. You can buy that separately at FAS/DPD Chlorine Test Kit


I am going back this afternoon to test again.

Watch these videos for how to properly do the tests...


You may benefit from having a stirrer - Magnetic Stirring Devices

I can't test the CYA because the test tube that was supposed to be in the kit was not there. Is there a way to test CYA without the test tube?

Nope.

Just add chlorine and keep pH in the 7's until you can test accurately. The TA is not very important to you right now.
 
Any idea what that could be?
  • Suction cleaner line
  • Suction for a leaf vac
I know that if all the drains are open, the water level in the pump drops and the pump will not prime.

By ALL, do you mean all four pipes or the three skimmer/main drain pipes?

Not sure if the leak is in the drain or the skimmer yet, but I know that if the 3/4" line is open, the water level drops in even if all three drains are closed.

So keep the 3/4" unknown pipe closed.

If I run the hose directly into the pump basket, the pump does not over flow except when I have one skimmer open and everything else closed.

Running the pump with the lid open is meaningless. The pump will not pull water from the pipes with the ;lid open.

If I start the pump with one skimmer open, the pump works fine. If I then open the other two drains, the pump continues to work fine.

How is this different then when it does not reprime after the pump is off?
But it the pump is turned off, it will not reprime and start again.

Is the equipment pad above or below the pool water line?

When the pump is turned off does water drain out of the pump basket?

Just trying to get a handle on the basic layout before I call a pool company to come look at it.

Have you check the condition of the pump lid O ring and drain O rings? And lubed them with Pool Lube - Further Reading

Wrap the four suction pipes and valves with Saran wrap. That will seal any air leaks in the pipes. If the pump primes with the pipes wrapped then you have a suction air leak in a pipe. Unwrap one pipe at a time to identify which pipe has the air leak.
 
By ALL, do you mean all four pipes or the three skimmer/main drain pipes?
Both, I've tested with the 4th line open and closed.

  • Suction cleaner line
  • Suction for a leaf vac
The Polaris vac, has a booster pump that it connects to. AFAIK it only uses water to vac debris.

Running the pump with the lid open is meaningless. The pump will not pull water from the pipes with the ;lid open.
I don't run the pump with the lid off but if the pumps are turned off and I put the hose in the pump to prime it, it does not over flow. I know there is one drain line that if open, the pump will over flow with water. Then I start the pump and am then able to open the other drains.

How is this different then when it does not reprime after the pump is off?
If all the drains are open and the water in the pump is low, if I start the pump it will not prime and will only pull a small amount of water from the drains. If I fill the pump basket and start the pump and then opne the drains, the pump will prime and pull water.

s the equipment pad above or below the pool water line?

When the pump is turned off does water drain out of the pump basket?
Yes, the equipment is above the water line and does drain when the pump is off.


Have you check the condition of the pump lid O ring and drain O rings? And lubed them with Pool Lube - Further Reading
The pump is brand new. I just installed it this past weekend. The o ring is good and I did lube it up.
 
The pump is brand new. I just installed it this past weekend. The o ring is good and I did lube it up.

All the symptoms say you have a suction side air leak.

Try the Saran wrap test.

 
You mean the K-1005 Test Kit?


That test kit lacks the FAS/DPD chlorine test to accurately test FC over 5PPM. You can buy that separately at FAS/DPD Chlorine Test Kit




Watch these videos for how to properly do the tests...


You may benefit from having a stirrer - Magnetic Stirring Devices



Nope.

Just add chlorine and keep pH in the 7's until you can test accurately. The TA is not very important to you right now.
I finally got the DPD test kit and the test tube to measure the CYA. Here are the results from yesterday's tests. I tested twice to make sure of the results:

Total Chlorine- 12
Free Chlorine- 12
pH- 7.5
Alk- 80-110
CYA- 100

I drained the pool for about 15 minutes before I had to leave. Water was about an inch below the skimmers. I'm gonna test again today, and probably have to drain more water. The app I was using "pooli" said to drain almost 6000 gallons of water, so I'm sure more fresh water will be needed.
 

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