Slow Leak - Too Slow For Dye Test?

[diyindux]

Last fall when I closed my pool I actually got some help from my family. But only to speed things up so that I could do something on someone else's list which meant that I had to get the cover on before I had all the other steps out of the way. Normally, I connect a hose to one of the returns on the stairs and shut all of the other returns and then use the pump to lower the water level, then I shut down the power, disconnect all the plumbing at the pad and blow everything out, then put the cover on. Instead, this time I used the help to get the cover on while I was lowering the water level, then shut down the pump and had to call it quits for the day. Two days later when I went to finish up I realized that I had never shut off the power and since the hose was still connected the pump emptied the pool while it was going through it's normal operation for the day. I refilled the pool as quickly as I could back to my usually winter level (took about 18 hours) but it dropped down to about 24 to 30 inches below the coping fairly quickly. I left it through the winter and just filled back up this weekend. The water was just about 2 inches below the top of the lights when I started and as I filled it, I went around with a pump sprayer with some red food coloring in it and checked around the stairs and the lights but couldn't find anything. I filled the pool up to about 1 1/2 inches above the bottom of the skimmers and left it overnight. When I measured it this evening, it had dropped 3/8". With my pool, that is about 200 gallons. That means I'm losing about 10 gallons per hour or about 20 ounces a minute which is a pretty slow leak. Is that something that a dye test can pick up? I don't think it's in the bottom drain piping since I could hear the air hissing out when I pulled the cap off the line to reconnect the equipment. I also am seeing the pump becoming empty and can hear air bubbling in the filter when the pump is off so I'm assuming that I need a new check valve as well. And my Bravo Fury has decided to only run for a few minutes at a time too just to make me feel extra happy to own a pool.

 

[CountryBumkin]

The dye test usually involves putting a drop or two within inches of the suspected leak then watching the dye to see if it moves towards (into) the leak. If the leak is small and there is no other water movement, eventually the dye will go into the leak. It won't work if you create a cloud of dye. One or two drops is enough to watch the movement of the dye.

The water needs to be still so there is no chance of wind or other causes moving the dye away form the leak. You would put a drop next to each light and the returns, and skimmer, and main drain (if you have one) then sit back and see what happens.

The trick would be to get the dye in there without disturbing the water much. One video I saw, the guy had an extension pole with dye injector attached to pole so he could reach down to main drain without being in water (without disturbing water much). I assume this video was from a professional pool leak tester (with specialized dye injector tool), but maybe you can do something similar. it wouldn't work if you had to be in the pool to inject the dye as your movement in the water would ruin the test (unless the leak is real big and you just sit there motionless watching the dye).

 

[diyindux]

Thanks for the reply. I was using a pump sprayer wand to deliver very small amounts of dye but it was definitely more than 1 drop. Maybe a syringe with a long tube will work. The water is still at around 50 degrees so I won't be in the pool.

 

[CountryBumkin]

You could just use the built in dropper from the food dye bottle (if your bottle has that style tip). Then reach in the water and squeeze a drop out near the area your testing. The key is to be able to watch the drop and see how it moves.