I can't believe you actually allowed these kids to tell you that you can't swim in your own pool. There are certainly things you can do, and the first thing to know is that if something happened to one of these kids while they're in your pool, you are liable for any injuries or death (even if you're not at home when it happens). You post signs on every side of your yard, stating that the pool is private property and there is no trespassing allowed. Next, you build an eight-foot fence that is wrought iron with spikes around the pool's perimeter (that tall, so it will discourage them from climbing over). You put a double chained lock (two locks) around the gate. If you do all of that, they will have been sufficiently warned. You also invest in a pool cover, so that when you're away for more than 24 hrs., your pool is covered and obviously closed. If something still happens after all of that, at least you've taken all legal steps to cover yourself. Here in Dallas, a couple of years ago, a teenager went missing while his neighbor was on vacation. The boy had been sneaking into the neighbor's pool and the neighbor had been having to keep chasing him off. While the neighbor was out of town, his pool had a cover over it to indicate it was off-limits. The police searched for a boy for several days, and then someone suggested that he might have gone over to swim in the neighbor's pool even though it was shut down. Sure enough, his body was in the pool, and he'd died there. His parents tried to sue the neighbor on the grounds that he was negligent, but because he'd posted signs and covered the pool, the judge found that the boy caused his own death by disobeying rules. The neighbor ended up removing the pool altogether and filling in the space with dirt. You don't want something like this to happen, so please take precautions.