After the 5 March bounce, Merlin was not acting right and he seemed dehydrated so we took him to the vet. He confirmed he was dehydrated and thought that he would feel better after he recovered from the trauma of the recent low and high BG. I was instructed to give him subq fluids as needed to keep him hydrated and to prevent constipation. Since his kidneys are working fine and he has no other medical conditions, the vet said if I gave him too much, he would just pee it away. I've given fluids to our house rabbits and other cats over the years so it was no big deal. I have been giving him 50 - 100ml/per day, as needed. If he is in the yellows or lower, he doesn't seem to need any. I think keeping him hydrated with the subq fluids has other benefits. He doesn't have to wake up and drink as much so he rests better and it lowers his BG by reducing the overall glucose concentration compared to being dehydrated.
He's feeling a lot better and ate a good dinner. He gets a bit off when he is in the greens. He used to be that way in the blues, but not lately.