I have a 450l pond and the Ph is regularly high
. Don't ask me for precise readings: I can only tell you that my testing solution is closer to dark blue that light blue
. So, my question is: what causes high Ph in the first place, and what measures, other than adding 'Ph Down', should I take?
Appreciate your help.
On a second matter, my pond receives a few hours of direct sun
from about 9am-12.30pm and dappled sunlight (trees everywhere here!) until 3pm. Given these conditions, what plants should I have that will thrive and possibly oxygenate the water?