Loosing antifreeze

No moisture in oil. I smell nothong at exhaust. Changed the old oil out. I see no leaks at freeze plugs, or anywhere else. I did pull one spark plug yesterday and it is very whitish. I have not had time today to do any type compression test or leak down. Storming again.
Maybe the rain will move East tomorrow and I can drive it down the road some and get temp up. Makes me wonder if the PO put some type of stop leak in it and it occasionally has an internal leak somewhere? I just haven't driven it but just down the road a ways and back. Too much stuff to do just to drive it and nowhere to go!! I need to sell down to a couple cars but....... I don't want to advertise this car till I know there is not a problem with it.