Hi, is there a better time of day to test PH/Alkalinity then others? I
notice I'm getting swings AM/PM of PH from 7.5 to 8.5 and my KH is
around 130ppm. I may increase KH to try and stabilize but the fish
seem healthy. Any particular time better then others to treat (add
chems) the pond?

BTW I'm using an aquamat and the fish seem to enjoy playing/eating in
them. I may get a couple of more as I have no plants (not sure if I
really want them). Are there any (taller) "grasses" one can keep at
the bottom of the pond that the fish can hide/play in?

Thanks.