There’s a few factors that can come into it that are not necessarily immediately obvious when it comes to adding first fish now. I have some of my own views on this also so will share and you can take away what you want from it:
- If you want a pure koi pond, don’t buy other types of fish as ‘canaries’ now that you won’t want to keep unless you already have their next home lined up for them. These are living creatures that deserve a home for life, or a guarantee of a suitable place to go on to.
- Fish feel safer in ‘shoals’ so buying a low number of larger fish is actually worse for them. E.g. 4 smaller ones better than 2 large.
- Don’t buy very very young or very small ones though since these might be less hardy. 20cm approx would be my lower end. Have you worked out how small a fish would go down your BD or skimmer?
- Starting fresh this is the time to decide on how to keep your pond ‘biosecure’. Have a serious think about how careful you want to be to keep KHV out of your pond. Buying only fully heat cycled fish, avoiding Israeli koi that might have received a ‘vaccine’ not approved in the UK, choosing a single source of fish- these are all things you should make a personal decision on.
- Pissing in your pond is a viable way of getting a nitrogen cycle going in your filters prior to getting fish. Male urine should be completely sterile, so no disease concerns at all about doing it. It’s easier to calculate the dose of ammonia from a bottle though and considerably less shocking for your neighbours :D Females shouldn’t piss in their ponds unless their garden is definitely not overlooked ;)