Pond Update

While looking for industrial strength pond filters, for which you have to pay an arm and a leg, I remembered that a friend who owns a local kennels had an indoor pond of similar size to us, with 30 or 40 huge koi and a couple of massive sturgeon in it. 

Last summer he sold all the koi and filled in the pond, simply because the cost of looking after so many koi was getting prohibitive in electricity.

I wondered whether he had any of the filtration kit remaining and, miracle of miracles, he has a Hydra 4000 with two 15,000 litre per hour pumps, which he wants shot of and I can have for free.

I can find no info on the price of a Hydra 4000, probably because it's no longer made. Chat GPT, however, maintains they are (or were) between £1,200 and £1,500. Two 15k lph pumps would be around £100 each, so using a 50% 2nd hand discount, I'm getting at least £700 worth of equipment for free.

I hope to collect them today. They might need a bit of fettling and I would need to buy an Evolution Aqua UV-C system capable of handling 30k litres per hour, with a 110W UV-C lightsource. Given the filter system is free, I can afford to spend a decent amount on the UV-C system - say £200.

Alternatively I could use a lower wattage and arrange some kind of bypass to halve the throughput. That might be the better solution, as the UV-C system can also kill beneficial bacteria. Thus far, we've never had to feed the 3 koi and they've managed to find sufficient food in the pond. If I kill all the algae and bacteria, then there may be a chance I also eliminate what the fish feed on, meaning I'd have to supplement their diet with pellets.

Given the system could turn over the pond contents within 5 hours, rather than running it continuously, I'd run it only a couple of hours a day, ensuring some algae remains.

I'd probably have to house the lot in some form of cabin, which I can get our tame builder, Colin, to make. He's famous for what we jokingly call "a shed-in-a-day".