Thank you for your question. I am sorry to hear your problem with water foraging honey bees. Unfortunately this is a very common problem during hot summers when honey bee foragers tend to collect more water for evaporative cooling of the hive and also for their metabolism. There is no reliable technique/way to deter these water seeking honey bees from coming to the swimming pool, but you can try to limit their numbers to the pool by providing few more attractive water sources closer to the hive. There is gap in knowledge regarding the exact amounts of each mineral that honey bees need, but it is known that they need Ca, Mg, K, Na. Hence, I am unable to provide you the exact doses of these minerals. You could try purchasing a mixture of salts (NaCl, KCl, CaCl2, MgCl2) and mix them in very small concentrations in water and provide it closer to the hives. You may also have to restrict the pool access to bees for at least couple of days by covering the pool during the day time, to discourage bees coming to the pool. As the bees are already trained to coming to the pool, without shutting access for bees may not yield good results even if you provide more water sources near the hives. Hope this information helps.