Steven

Sorry to hear about your koi , I’ve not set up my arowana yet! -but koi I do have experience with. If you believe a ‘joker’ turned off your pumps-a sign left on it not to be touched, might be the first thing they go for?

In my experience, It’s best to have all your switches locked away in the pump house, and where possible have your air pump on a different circuit to the rest. With a back up generator-just in case.

I’m a firm believer in you can never have enough good bacteria and air supply for koi. So I have a filter block that is half the size of the pond, nothing special just tubes and rock. No vortex,skimmer or any of that high cost filteration equipment. Koi are hardy fish and the more you add-the softer the fish become! and prown to diesease.

Sadly, alot of people do not realise, primarily, you are keeping water-and the fish come along for the ride! I’ve just had a simular thing happen to a friends tank of ‘gold form’ ancistrus. They awoke in the morning to find over 8o of them dead. They thought they had a perfect set-up? Flugel filter that adds air through a venture at the surface and a tank full of plants and fish. With the warm weather not helping(less oxygen in water), the amount of baby fish-together with the breeding pair and off spring from other breedings, together with the plants that supply O2 during the day-but give out deadly CO2 at night(something else alot of people do not realise)-The system was on borred time!-All I could do was and a decent air pump so hopefully it wont happen again?

A fresh supply of constant air(pond/tank and filter) is most important and the only expensive bit of equipment I bought is a jap made ‘MEDO’ air pump with a 10inch airstone disk. Theres lots of makes on the market-but most have flappers that have to be replaced, This one is like the old fashion british enginnering pump you used too be able to buy-with a piston instead. In the four years it has been running constantly?-it has never broken down or stopped. Once a year it just needs the external air filter washed out, and I’ve hand no health problems with my koi-since!. Simon

p.s. Thanks for all the tips and the advise you provide here, its very usefull x