Hi all! new inflatable tub owner! 2 questions. 1. i have an inflatable lid that is brand new but after a day or two i need to add air. is that because as it sits on the warm water it expands, and then when i take it off and set it aside, it deflates some because of temperature? i cannot really tell if it is fluctuating because of outdoor temps or if i have a leak and what is really normal. question 2 - shouldnt the heater work like a thermostat? if i set it to 98 i feel like the digital reader will go down to like 90 so i have to reset the heater. shouldnt that be restarting on its own to keep the water ~98 when not in use? or am i jumping the gun because the water is sitting so the thermometer isnt showing a true temperature so it might be showing a lower temp that it actually is? i am completely new to this so not sure what is normal or if i have bigger problems. thank you in advance for any responses.