Few things are worse than going outside on a bright sunny day for a relaxing dip in the pool and finding a snake in it. For as long as pools have been around this has been a problem. There are as many ideas as to how to keep these slithering intruders out as there are varieties of snakes. Unfortunately very few solutions work, but there are a few things you can do to cut down on the likelihood these uninvited guests will crash the party.
The first step to keeping snakes out of your pool actually has nothing to do with your pool but rather your yard itself. Make your yard an unattractive home for snakes. You can do this by mowing the lawn regularly and keeping it cut short. Snakes generally do not want to be exposed to the hot sun, they enjoy a cooler temperature and comfort. In addition this will help you spot any that do decide to enter your yard anyway. You'll also find that snakes love shrubs and pipes as well as hiding out under decks. To help minimize their taking up residence around your home and flower beds go light on the mulch and bushes against the house keeping it from accumulating over two inches. Keep firewood piles well away from your house an pool as well as any compost or mulch piles. Keep the area under decks free of debris. A clean yard that is unfriendly for snakes is the best first step to keeping them away from and out of your pool.
Many people have natural or "old farmers" tricks to keep snakes away but the reality is most just don't work or come with a trade-off that makes them unattractive options. I was always told that placing raw garlic around the perimeter of the pool would drive snakes away as if they were vampires so this was something we tried briefly. No snakes went in the pool over the ten days or so we tried this but neither did any people. The amount of garlic needed to be sufficient just created too strong a smell and it didn't take long before we had to shut the windows to the house to keep the smell out. Luckily no neighbors were able to pin the smell down to originating from us. Granular sulphur is said to work like a magic bullet which burns the snakes belly when they slither over it, and again it is true this does work. However when you create a perimeter of this to keep your pool safe it will also burn your feet if you walk over it barefoot as well as your pets paws. If you have kids this is an especially awful idea. Plus, every time it rains it washes away and/or dilutes and you have to re-spread it.
One remedy that worked to some degree was boiling pouches of chewing tobacco and then spraying it literally everywhere around the pool and yard. It did keep bugs off the plants and deer from gnawing on our shrubs but a couple of snakes made there way to the pool anyway. This actually seemed to work decent, much better than mothballs which have a strong aroma and any variety of snake repelling powders. The thing is snakes just go underground, up trees, or who knows where to find a way to get to their target destination regardless of what we spread. They may be many things but they are not dumb creatures.
The next summer we went high tech and bought an electronic snake repellent which was supposed to emit a high pulse that causes vibrations. The vibrations are said to scare away the snake almost immediately as it is supposed to trigger their "danger center." One unit was supposed to protect an area of forty five feet but per suggestion at least two (More was really suggested) units that could overlap each others area were supposed to work best. It did make the dog and cat curious, but it did not keep snakes out of the pool. With yet another failure in place we called in a professional to help us.
We were given two options to keep snakes out of the pool although we were told neither could be one hundred percent certain.The first and most expensive was to enclose the pool in a lanai. This seemed like overkill but we kept it as an option. The animal control specialist was at least honest enough to admit that over time snakes would eventually be able to breach the enclosure unless we built something akin to a cement barrier fortress around the lower three feet of the lanai. The second suggestion was to just get a pool net. The idea of securing and removing it each time we used the pool seemed tedious but it was better than a construction project. We purchased a net that day and now in it's sixth year of use we have only had one black rat snake in the pool, a far cry from the days we had two to three each week.
While using a net may seem cumbersome it is the most effective way we found to keep snakes out of the pool. The farmers remedies, electronics, and special repellents just didn't do the job and over the long haul end up costing more than a net with unwanted side effects to boot. Sometimes the simplest solution is the best.