I’ve Sprung a Leak – “Fix a leak” Review

I’ve Sprung a Leak – “Fix a leak” Review

I’ve had a small leak in my hot tub now for some time. Nothing too drastic, couple of centimetres / an inch of water a week that I have been topping up.


I thought that this would be a good time to review the “Fix a Leak” product from Canadian Manufacturer Marlig Industries. They have specialising in this leak repair industry since 1980. I know that a couple of my customers have used this product before with success so let’s see how I get on.

Fix a Leak Product Size and Availability


Fix a leak is a blended, concentrated material designed to seal leaks in virtually any material. Fix a leak can be used to fix pool and spa plumbing leaks, pool leaks and spa leaks. It will seal holes up to 3mm (1/8”) in diameter and form a permanent seal.


This product is best used in fully foamed or a pre-built wooden hot tubs. Use 8 oz per 500 gallons for leaks in hot tubs. Use 32 oz (910 ml) for pools up to 18,000 gallons. Two treatments are required for large leaks. Leaking pools, plumbing and pool liners can all be fixed with Fix-A-Leak!!


The product is available in two sizes 8oz and 16oz – for my Spa, I am going to use the 8oz bottle which is 235ml. Pretty inexpensive to be honest.


Features of Fix a Leak


  • It is a concentrated blended material.
  • Seals leaks in virtually any material.
  • It works well in the plumbing system.
  • Seals holes up to 3mm in diameter.
  • A long-lasting seal is formed.
  • Spas only require 4 oz for 250 gallons.
  • It will not harm salt chlorine generators, heaters, pumps or filters


What is the Application Process?


*Shake Well Before Using*


For Spas:

  1. Remove all cartridge filters before adding FIX-A-LEAK to the water.
  2. With pump running, add FIX-A-LEAK slowly through skimmer or in front of any other suction intake. 
  3. FIX-A-LEAK must be re-circulated continuously for at least 4-6 hours per day, possibly for up to 2 days or until you have determined the leak has stopped.
  4. The product is very heavy and will settle to the lowest point rather quickly. It must be stirred back into suspension every 2-3 hours during circulation of the water.
  5. After the leak has stopped and given proper cure time (24-48 hours) you may return to normal filtration. *NOTE* When reinstalling your cartridge filter(s) run spa in it’s normal cycle for a period of 6-8 hours to collect any residue. Now remove filter(s) and rinse immediately under warm water before re-installing. You may have to rinse a second time. 
  6. Treatment can be repeated if necessary.


For Swimming Pools


  • Bypass FILTER MEDIA before adding FIX-A-LEAK to water. Sand filters: set filter valve to recirculate. Other types: remove cartridges DE elements from filter tank. Then proceed to circulate through empty tank.


  • With pump running, add FIX-A-LEAK slowly through skimmer or in front of any other suction intake.


  • After adding FIX-A-LEAK adjust suction to main drain. If this is not possible, the vacuum cleaner could be used alternatively, simply by placing the vacuum in deepest part of pool and connect to normal vacuum connection. Set filter valve to normal vacuum position.


  • FIX-A-LEAK is very heavy and will sink to the lowest point rather quickly. It must be stirred back into suspension, either manually using a pool broom or mechanically with a automated pool cleaner every 4-6 hrs. during circulation of water.


  • Continue to recirculate water until the leak has stopped.


  • Mark level of water in pool and check for 2-3 days to determine if the leak has stopped.


  • After the leak has stopped and given the proper time to cure (24-48 hrs.) you may return to normal filtration. Sand Filters: Set filter valve to filter and resume normal operation. Backwash out unused FIX-A-LEAK as required. Other Types: Reinstall filter into tank and resume operation. Rinse out unused FIX-A-LEAK from filter as required.


  • *NOTE* Never let cartridges of DE elements be left to dry before they are cleaned.


  • Treatment can be repeated if necessary.

What about my leak?


What is slightly different about my leak is that I know exactly where it is. It is at the bottom of my skimmer and I know that it is because of a bad joint.


I remember struggling with this particular joint when I built my hot tub, then afterwards, finding that I used the wrong adaptor as I found the correct one in the box. Doh! So I botched the joint! Guess what – it now leaks. As I always say, joints not made correctly will eventually fail and leak!


When I did my control room remodel last year, I didn’t realise that it was there otherwise I would have cut it out (it is encased in concrete) and remade the joint – my bad! I always recommend if you know where the leak is, cut out the joint or pipe and re-make the joint. This is always the best option.


However, as I can’t get to it easily, well, not really at all as there is a load of plumbing in the way now too – I am going to give this product a go.


My Approach


As you will have read in the instructions above, you are meant to recirculate this product through the plumbing. Now, the logic here being you don’t know where the leak is.


However, I do, so I am going to try and focus my efforts on this area – e.g. the skimmer and see that with a concentrated dose of the product, I can actually seal up the leak.


First, I am going to drop the water to just below the skimmer so water is not entering from the top of the skimmer. Then, I am going to close the gate valve from the suction side of the pump. This means that I will now have a “captive audience” of water for my treatment.


I’m going to put the bottle into the skimmer in stages, stirring every hour or so today and topping up with water until it holds which should be pretty easy to monitor.


Let’s Get Started


I killed the power to the tub as I don’t want the pumps to run for this, I will manually “circulate” eg stir the water every hour or so throughout today. I have closed the gate valve so the water in the skimmer is now isolated.


I added about 1/3 of the bottle and the water went cloudy very quickly. I also topped up the water in the skimmer to a point where I can see what kind of a loss we are looking at.


I also stirred the water to make sure that the solution was well and truly mixed in. Now time to leave it for an hour or so before I go back and stir again.


After a Couple of Hours


After going out to stir up the water every hour or so, religiously, after about 4 hours, I thought that it would be a good idea to open the gate valve. There was no water loss so I thought I needed a bit more pressure to try and create some. The reason being is that I wanted to increase the flow of water, with the fix a leak solution in suspension, through the leak at the bottom of the skimmer.


The product works by binding to the hole and slowly blocking it up so I thought that this would be a good idea. What I did notice straight away was that there was considerably less damp areas around the bottom of the skimmer – could the product be working already? At this point I’m just over half a bottle in.


8 Hours In…


After 8 Hours, I decided that it was time to fill up and get the heat back on. The ambient temperature is quite low at the moment so I didn’t want anything freezing up. Having done my little science experiment – watch the video on this page if you haven’t already – I knew that it was probably cured in already as I was not circulating the water and doing a concentrated dose.


All filled up – time to see how she holds up over the next few days. There was already less visible dampness around the skimmer so I am confident things are going to be a lot better already. Pretty impressed to be honest.


The Next Morning….


The next morning, I went to take a look at the water levels. I should have measured the exact depth with a ruler the previous night but I didn’t. Visibly, there was little to no movement on the water level in the tub from the mark that I had placed on the tub.


However, in the control room around the skimmer, there was still some water, so the leak had not yet been fixed. That said, it did say on the bottle that it takes time to cure. So, what I have done is poured the remainder of the bottle into the skimmer after turning off the circulation again and I will see how this second dose works. With the water level pretty much perfect, hopefully the extra “weight” of the water will get the solution into the areas that need sealing.


Watch this space.


24 hours on…


24 hours on and I went back to my hot tub with the ruler to check the level. It had dropped a couple of mm in 24 hours which is not a lot at all. Pretty happy with the result at the moment. Now, it does say on the bottle that a second treatment might be necessary so I might look at doing that. However, very pleased with the outcome – this is a great product and I am sure many DIYers like me will be making use of it!


Happy “leak free” Hot Tubbin’




Can I Help You?

If I can help you in any way I would love to hear from you. You can get in touch using the form below.

Thanks - Andi


Hi, Andi here. I own Buildahottub.com and also write all of the articles and info pages on the site. Some years back now, I built my own hot tub but struggled to find the information I needed. So, once my tub was complete, I started this website to help others in their own pursuit of hot tub and plunge pools DIY building information.

Today, I've helped over 1000 DIY customers just like you all over the world build hot tubs and pools. Have a good look around the site, there are lots of resources here. Please do get in touch if I can help you. - Cheers, Andi

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