Quick DIY tips on fixing a leak in swimming pool in Sydney

Sharing my experience in fixing our swimming pool leak in Sydney.

When the pump was running, the water level would drop below the skimmer box level in 3-4 days. I put off fixing it because I imagined it would cost a bomb. Eventually, bit the bullet and decided to tackle the leak.

First a disclaimer, pool leak detection is a separate trade of its own. The pool detection guys are prepared to dive into the pool and check the nooks and crevices. Plus they have equipment like sonar and camera that can pin point where the leak is under ground. For most folks, probably worthwhile to look for a specialist pool detection guy.

But if for some reason, you want to go down the DIY path, looking back, it is possible. Read on.

I contacted 2 pool leak detection specialist. Going rate is around $500-600. One person quoted $500 (but guarantee to find the leak). Another person quoted $250 call out and $500/hour after that... It would typically take 1-1.5 hours so $500-700 was his ball park estimate.

I ended up finding a pool technician (Andrew was his name... a nice bloke)... It was not his trade but he has done it for other folks. Andrew charged $100-110 per call out.

1. There were no visible cracks along the pool (wall and bottom). So big sigh of relief.

2. First step... Used the leak detection kit (literally a syringe with dye). Pic 1. Places to check => skimmer box and the various returns are the obvious spots. One more spot to check is actually the pool light. May need to take the light off the wall to do it properly because the electric wire goes through the concrete and the silicone around the wire may have weakened over the years.

3. No such luck (obvious leak) for us after the first pass. Andrew then used the water pressure tester on different returns (outlets in the pool). Idea is if there is no leak along the pipe, pressure will hold constant... If there is a leak, obviously water pressure will drop. Again, no luck.

4. Then resorted to the dumb and slow way.... We simple let the water evaporated.... Idea is once water level goes below the leaking spot/return, water level will hold... Remember the water level was dropping by a skimmer box height every few days.... It took us a few day.. Eventually, water level dropped below multiple returns (higher up the wall) but kept falling. Then Andrew put in 2 separate rubber plugs (Pic 2) on 2 returns lower down the wall (but still submerged). Lucky... Water level stopped falling. We knew the leak was in one of the two returns/pipes.

5. Now an important question is how to fix the leak..... There are two ways... Fix the leak properly... Remember the pool leak detection guy can pinpoint where exactly is the leak under ground..... Next step is he or she will recommend someone to do the actual repair of the pipe. This is where you can get killed... Just imagine having to get another "specialist" involved and then he has to dig up the ground and find the pipe and do the repair and then put everything back and maybe re-pave the pool surrounding area...

6. Or the easier way... We worked out which one of the two returns was leaking. In our pool, because we have several returns, we decided to block the return instead of fixing the leaking pipe somewhere under ground. Fairly easy and quick..... Took the rubber plug... pushed it deeper into the pipe then tightened the screw on top to expand the rubber and locked in its position. Then we used Maxplug (Pic 4.. around $30 for a small tub at Bunnings).... It is a VERY quick set hydraulic cement... Literally mixed it with water, formed a ball, then slapped into the return/outlet to seal in the rubber plug. NOTE.... the Maxplug set VERY quickly (turned into rock hard cement) in 1-2 mins at most... so do it fast. A tip is it is worthwhile to cover up the surrounding area when applying Maxplug because the grey smudge is hard to clean.

7. Another alternative is instead of using Maxplug... Can seal the rubber plug with Aqua Knead or Emerkit (under water putty). See Pic 3.

8. Then you have a choice... How to conceal the return (now greyish looking with Maxplug hardened into cement) ? ... Quick way is to plug in another eyeball to the return... Or, in our case, I just pebblecrete over the return. See the Pebblekit recommendation.

9. In our case, we actually drained the pool because the leaking return was quite low down the wall. We had to refill the pool and then rebalanced the pool. Just extra info... Our pool dimension is 9M x 4.5M... Chemicals required to rebalance the pool = 10 bags of salt, 2 4kg buffer, 2 5kg calcium hardener, 2 3kg stabiliser, and 15L chlorine.

10. One more tip is the leak detection specialist won't jump into the pool if water is green/algae.... So need to top up with chlorine weekly to stop algae in the pool when the pool is being drained and pump not running.

All up, it took 3 outcalls from the pool technician... $300-330... Plus Maxplug $30 + rubber plug $20. Plus the cost to refill and rebalance the pool (another $400 or so).

Fixing the pool leak turned out to bearable (under $800). In hindsight, while DIY is possible, maybe better to work with a leak detection specialist if urgent.... Where it takes careful consideration is how to fix the leak ? Digging anything up is going to cost a bomb....

Leave a comment if anyone wants Andrew's contact details... It is not his trade and he prefers not to have to do leak detection.