Sleep mystery solved?

For the last few weeks I've had trouble getting a decent night's sleep. Last night saw me once again staring at the ceiling at 0400, having just woken up after getting to bed on time. As I tossed and turned for the next few hours, I eventually noticed my legs getting restless. I'd never noticed that before at that time; usually I notice it as I'm trying to fall asleep for the first time in a night, which is typical of most people.

Now, restless legs, like their equally evil twin leg cramps, have to do with your sodium-potassium balance. My anti-androgen, spironolactone, makes one pee out everything except potassium, a "potassium-sparing diuretic" in docspeak.

Getting back to last night, as soon as I had a glass of water, my legs calmed down and I fell fast asleep - around 0700. I've already cut out eating the salty stuff spiro makes me crave after 2100 because I don't want to have to get up during the night. What I'm going to try is drinking lots of water between 2100 and, say, 2200 to see if I can get a handle on this.

Mind you, this could be my annual late winter insomnia, but it seems to be worse than usual. And I really did have restless legs this morning.