Hi, many thanks for the feedback
. Some further info in case its relevant:
The pond (pics attached) is about a year old, and holds about 3000Lt (800 gallons), max dimensions 2.7m x 2.2m x 0.9m. It has a Hozelock pressurised filter system with UV:
- Bioforce 4500UVC filter rated for 1000 gallons
- Titan 3000 pump rated for 3000 Lt/hr (660 gallons/h)
The filter seems prone to blockage, and if I don't wash out all the sponges in it every week or so the flow reduces to a trickle. The flow from the filter enters the pond an inch or so above the water level.
There about a dozen fish, six koi averaging six inches, and six goldfish averaging four inches. There's not much planting as the Koi seem to eat it all. There are quite a few frogs (plus tadpoles in the basket). So far, I've not tested the water chemical composition as I wouldn't know what to do with the results. I live in Chelmsford, UK; and I don't know of a KHA hereabouts.
The red on the Doitsu Koi does not seem to be getting worse, and the light grey spot on the Chagoi has got a lot smaller in the last few days (though the blackish surround to it is the same size).
I would appreciate your advice on
- does the pond have a parasite problem? Will a testing kit show this or just show chemical composition? Should I add to the water something like Hozelock's anti-parasite treatment?
- should I leave the Chagoi alone as it appears to be recovering?
- is mercurachrome and Lamisil (for the Doitsu) something I can get from a pharmacy? Should I do this as well as or instead a anti-parasite water additive?
Many thanks.