I've enjoyed reading and keeping up with this thread and it’s motivated me to finally make time to sort my pond out. However, I seem to have distressed the fish and I could use some advice.
I think there's a ghost carp (8-10") and a handful of smaller shubunkin or koi (6x 4-6”) in a roughly 1000L pond, although I'm happy to be corrected on that - I have no fish experience! This photo shows them looking happy enough (I put some koi food in to get the photo).
The larger fish is now staying static (fins moving) under the plant in the middle of the pond & I’ve only seen one of the smaller ones hanging out with it. Presumably the rest are hidden away too (they usually follow the larger fish around anyway).
The backstory is that I moved in to this house a couple of years ago and the stream leading to the pump/filter would run dry every other day (losing ~100 litres of water). Needless to say, I haven't been filling it up every day so the pond has been filterless for a couple of years barring short periods following rain. The pond wasn't looking too bad though and the fish seemed happy enough. I used to just pull out the excess algae growing at the sides of the pond a couple of times a year.
Anyway, following inspiration & advice from this thread, I found the stream was suffering from some bad capillary action at the two joins in the liner. With those resolved, I'm now losing no more than a few litres a day so some work still to do but a considerable improvement! The stream runs for at least a week with no rain. I’ve also done some general tidying within the pond - I lifted out a dead plant and cut back dead shoots on a lily. The water is now fairly clear (showing the massive pile of dead leaves & algae at the bottom of the pond!) and I bought the Colombo water test kit and ran a test. All values seemed to be as expected (pH 7.5, GH 12, KH 10, ammonia, nitrate & nitrite all 0, phosphate ~0.25mg/l).
So, why are the fish so sad?
After getting the stream working and taking the dead plant out but before any further tidying of the pond itself, I gave the fish some koi food which made them all come up so I could see them (first photo above). Since doing the tidying, they stay submerged and ignore any food I drop in. Presumably it must be one of (or a mix of):
- Stress at the change
- Stress from the disturbance during the tidying
- Lack of cover in the water (although there’s still a fair bit) or extra sunlight
- Poor oxygen levels (but with the pump/waterfall now going and that much algae, surely this shouldn’t be the case? The fish are also towards the bottom rather than coming up for air)
- Change in temperature
Any advice appreciated.
Pond view:
Frogs/toads still seem happy enough (see under rock):
