So I did install the UV light and as promised, it cleared the green algae in just 2 days!
Everything seemed to be going fine for a while, but then ths weird black algay grew almost overnight first on the waterfall stones, then on the walls of the entire pond, making the water look dark...it is now still clear (I can see the bottom and all the fish just fine), but the walls are covered with this black algae, I've never seen before!(a bit smelly too) and the whole pond looks so dark, I worry that this new algae can be harmfull for my fish!
I do not want to add chemicals, but I need to know: are my fish ok in this condition??
pond size: 3000gl
fish: 12 (10 koi, 2 shubunkin) 15" average
Ammonia: 0
Nitrite: 0
Phosphate: 0
PH: 8.5 to 9 (always been high)
Everything seemed to be going fine for a while, but then ths weird black algay grew almost overnight first on the waterfall stones, then on the walls of the entire pond, making the water look dark...it is now still clear (I can see the bottom and all the fish just fine), but the walls are covered with this black algae, I've never seen before!(a bit smelly too) and the whole pond looks so dark, I worry that this new algae can be harmfull for my fish!
I do not want to add chemicals, but I need to know: are my fish ok in this condition??
pond size: 3000gl
fish: 12 (10 koi, 2 shubunkin) 15" average
Ammonia: 0
Nitrite: 0
Phosphate: 0
PH: 8.5 to 9 (always been high)