Originally Posted by
tamsin
The gardener put a tank, around a meter high, with two sacks of stones in it. Then a white fiber filter is laid on top of that, which gets changed every 3 days, or whenever I see water pouring through the outlet hose. He'd originally put the hose in the original pool drain and it almost drained half the pool before I'd noticed.
Why are you changing the white fiber stuff every 3 days ?
That water coming from the outlet hose should be going back into the pond (not the drain).
You pond has 40,000 litres of water in it. It needs a substantial filtration system (that 40,000 litres should pass through the filter twice a day(at a minimum) ideally every 2 to 3 hours though). as it is a pool it should have a bottom drain in it.
Google bottom drain koi pond filter.
Adequately running a pond of that size (filtration, aeration) wont be a 500b per month exercise.
Also, get some sucker fish.