Hi all

Newbie here please advise.!!

Pond is about 9 months old with a 55Gal Biofilter + (UV installed this week)
Plus a newly setup Veg filter 300gals
Plus 2 waterfalls (in and out of veggie filter) for oxygenation
2000 Gals in total

Water Temp 60 degrees (Noon today)
Amonia= 0
NO3= 0
NO2= 0
PH= 8.5
dKH= 4.5
dGH= 21.....................????!!!
Salinity= 1%

15 fish all under 9" mostly Koi

Water Hyacinths are browning and curling up at edges as is Water
Lettuce.....!
Although yesterday having read various postings on web I added 1 tablespoon
Potash

This dGH reading is worrying me ..what is it telling me?
Anyone have a solution please

Many Thanks

Regards
Chris