Leak detection help

[diasurfer]

In April, I posted about a couple of issues that I had while getting the pool going for the swimming season. One was CYA loss over the winter, and one was black algae. I solved the black algae issues but it is now clear that the source of CYA loss is a leak.

I pretended it wasn't happening all summer but now it's too much to ignore. I have read the part on leaks in the Pool School and will report back once I have done the tests described there to diagnose where in my system in appears to be happening. My question now is how to plug/stop up the various entries and exits and entries to the pool 'vessel'.

I have a skimmer in which the bowl is formed into the concrete that forms the pool, if that matters. Should I stick a tennis ball down the pipe?

What about main drain? Remove cover and stuff something in there?

And I have two jet returns. I have never touched these in any way since I bought the house. Is there an outer portion I can remove to plug? With what?

Or do drains/skimmers/jets have special plugs that I should buy at a pool store to properly seal them for a leakage test?

 

[JVTrain]

If you're wanting to plug holes in returns or skimmers, expandable plugs of the proper size are the best bet.

These plugs also work for only returns or some skimmer connections.

All you'll need to know is the size of your fittings. Typically they are 1.5" or 2".

 

[diasurfer]

Thanks I was able to get my two returns plugged and the skimmer and drain. Pool is still leaking water so it appears it is the pool vessel.

We have a large crack in the side of the pool which has apparently been there for years. Last week, before I had the pool plugged (it shouldn't make any difference now) I tried the food coloring test next to this crack and it didn't appear to be drawing anything into the it. However, I was doing this test from the surface so couldn't check deeper than a couple of feet from the surface. But it seems like it's impossible to do the food color testing if you are in the pool because the waves and currents induced by my body moving around are stronger than the leak.

But I also did food color test around the old light window, and the bottom drain, and in the area around the returns, and didn't see anything then either. (Again, this was before I plugged inflows/outflows, but that shouldn't matter it seems.)


But I really don't have any choice do I? Assuming my plugs are water-tight, it appears to be in the pool vessel, so I have to use food coloring to find the leak - is that correct?

Maybe I should post pictures of the crack. My old pool guy said old pools like mine have very thick concrete walls and he doubted that the crack went all the way through.

 

[diasurfer]

I did the dye test with all returns, skimmers, and drains plugged and it does appear that the crack is the source of the leak. It's drawing dye injected outside the crack. I'm 90% sure - not 100% since I haven't done this before and there is a chance my motion is causing the dye to move into the crack.

Assuming it is a leak, what are my options? As you can see from pics below, the crack extends up to surface tiles. It extends almost full depth of pool. Reworking soil outside of the pool, if that's what it requires, is going to be a major expense since it is all under patio tiles and pool is inside screened enclosure.

Any advice?

 

[diasurfer]

I just repeated the dye test and the crack definitely seems to be leaking water. A pool repair pro is coming over later today to have a look.

Any other comments or advice? Anybody?