First off, they haven't scarred yet. They should still be in the early parts of healing. Secondly, hot tubs are filled with bacteria and germs, and hot water can cause wounds to become inflamed and damage tissue (though I don't know if the hot tub water is hot enough for that to be of any concern). You really should not have gone to the hot tub if your cuts are still healing. I feel like this is basic common sense. Why would you think that hot tub water would make your cuts heal better? You shouldn't be going to a hot tub, going to a sauna, etc if your cuts are still in the middle of healing. All of these activities should have been avoided for 2 weeks after injury, if not, longer depending on how deep your cuts are.