Marlig Industries Pool Leak Sealer - 8 oz Fast-Acting Waterproof Sealant for Inground & Above Ground Pools - Stops Leaks in Pipes, Liners & Filters - Easy DIY Repair Solution

We have an older hot tub. We shut it down in the summer because we don't use it that much when it's hot outside. We must have some small cracks somewhere in the plumbing - we haven't been able to find them. Every year when we fill it back up and start it, it is wet around the tub the next day and almost an inch of water has leaked out. I order a bottle of Marlig's Fix Pool Leak Sealer, slowly pour it in, run the tub for an hour and the next day it's nice and dry around the tub. It Works! It's also a whole lot less expensive than having someone come and tell you that you have a cracked pipe or leaky connector somewhere, but it can't be found because it must be buried in insulation somewhere.We were losing half our water every week (hot tub is a little larger than 8'*8'). I gave up trying to fix it because it's an older hot tub (pre 2008) that came with the house, and everything I was reading said it was junk at this point. Figured this was worth a try since it was a whole lot cheaper than a service call. One bottle all but stopped the leak! I am losing maybe a few mm every week. We're going to do one more treatment for good measure and hope this stuff lasts awhile.This works great for most hot tub leaks. It will seal up to 1/8 size leak on the OUTPUT SIDE OF THE PUMP OR PIPES. It can not seal a leak if it is on the suction side unless you apply it directly on the outside of the pipe and then let it get sucked in and cure.It will seal fast in 2 days. However after about 30 days you may see the leak resume this is from the material curing and the vibration of the water flow. So you want to do it a second time to seal and additional leaks.I suggest getting the 32 oz bottle. That will easily do a 10 x 10 hot tub at least 3 times if neededWe had a really leaky hot tub and was dreading pulling a fully insulated hot tub apart. I was explaining to a friend the dilemma, and he told me about these types of products. With some research I went with the Marling product and low and behold, it worked! Follow the instructions, have hot tub at 100°, remove filter, keep it running, and stir up the bottom, seats with a soft broom every hour. The only thing that kinda sucks is cleaning the filter a couple of times.Suggested by my spa guy to fix a small leak, easier than taking the spa apart even though he saw where the leak was coming from. Added per instructions, cycled for 2 days, drained and refilled. Worked like a champ! I figure the leak stopped almost within minutes of using this stuff, but let it run in regular mode for 2+ days or so before draining.I plan to maybe add half a bottle every 6 months or so. It was not messy at all and very easy to use. I believe it is basically silica gel that fills the weak points. Spa back to normal.Squeeze 1/2 the bottle down into each of the 2 filter bays, submerge bottle under water and squeeze it out while the spa is running. Hope it holds, time will tell.This review is after a week and applies only to outdoor recirculating fountains. After trying a number of other unsuccessful ‘fixes’ this stuff appeared to work pretty quickly (miraculously?) but the leak returned after a couple days; gave it a second dose, again seems to have worked. For fountain application it’s ability to penetrate everywhere water goes is a far, far superior fix to using spray rubber, epoxy, aquarium sealer, etc, as 1) the problem is often deeper than a surface sealer application can reach and 2) fountain cracks open up more with the full weight of water, so fixing it ‘dry’ is no good. I’ve even used underwater sealer but you’re still limited to the surface you can reach — and cracks from freeze/thaw often occur in inaccessible areas (even on an empty fountain). For small fountains, bird baths, etc that only hold several gallons of water, the smallest 8 oz bottle for under $15 is plenty for a number of applications…and even if it periodically needs a booster shot, it’s still the best solution by far to all alternatives for any persistent leaker. Think of it, in the light least favorable, as the easiest, cheapest, quickest, least labor intensive option that may work and you should try it before anything else for leakers. Word to the wise: if you don’t exchange the water after a couple days birds and animals will avoid it while it still has the chemical aboard…but it doesn’t seem to harm ground cover when dumped on it.I hired an honest spa repairman when my spa started leaking 6 or 7 years ago. He said he could charge me his hourly rate to look for the leak and then fix it, but that it would be easier and a lot more affordable to buy this product. So, I tried it. It worked. And I've been using it every 2 years or so to keep my spa running.