The pond which is part raised underwent a major refurbishment at the end of last year and now comprises of an upper pond of 968 litres, and a lower pond of 4293 litres. Water is pump fed from lower pond through a 55 watt UV into a Nexus 210 and back to upper pond and returns to lower pond via 2 water blades. There is an additional water cascade in the centre of the pond so I believe the water is well oxygenated.
The adult fish are in the lower pond and include the 3 Orfe, 5 Shubs and approx 15 assorted comets/goldfish. We also have approximately 1 dozen assorted fry new this year that have found there way into the upper pond and are doing well. There are lillies and water hawthorn in the lower pond and the upper pond is stocked with a variety of mainly native water plants.
I perform regular weekly water changes using a spray head on the hose and dose with sodium thiosulphate. I last tested the water on 1 August using NT Labs liquid kit and the results were
PH 7.5
NH3 0 (light straw colour rather than the deeper yellow on colour chart)
NO2 0.1
NO3 5
KH 7
GH 9
I am currently treating the pond for blanket weed with pink crystals, viresco aqua and viresco digester.
I have tried photographing the fish without removing it from the pond. Whilst the results are not brilliant they give some indication of the issue. Your thoughts on what the problem might be and suggestions for treatment, if any, would be much appreciated.
Thank you.



