Any pond success stories??

Don't bother with fish until your pond is well established. They'll only die or get eaten by a heron.

Let the pond get properly sorted, growing for a year, ideally attracting frogs, damselflies etc. Fish need decent and stable levels in the water in order to be healthy. The first season of a pond can have it veer from one to the other until it's a self regulating ecosystem. It's the same with an aquarium, but that's much smaller and under your control with things like light and temperature. A pond need to be healthy and established.

After that, decide if you want to add fish.

Edited to add - successful pond here for 17 years with both wildlife and fish

Never once tested my water. I threw in roach, they proliferated, I had to re-home them. I currently have goldfish, they have a filter, mini waterfall which splashes so oxygenated water. They’ve recently reproduced. Whilst I don’t advise adding fish if they’re likely to suffer due to poor water quality, you can buy fish over the internet. I’ve seen dead fish floating in the local nursery/aquarium, I bet their water quality is crap.

I occasionally top mine up and add the dechlorination product, doesn’t matter how long it stands, the chlorine will never really go otherwise.

Oh, world of fish

We have an above ground pond now.if you want fish,you can't top up the water level with a hose. We've got water butts, otherwise you have to leave tap water in containers for 48 hours to dechlorinate. We have got rid of most of the plants, apart from a rather lovely water lily. We don't use chemicals when we first introduced fish,we used barley straw blocks for the weed. We now have an electric UV filtering system, which also has mesh filters. They do need cleaning regularly. A fountain to oxygenate the water. We are in the SE UK it's been mostly in the high 20s, even around 30c a few days, and the water evaporates. In winter the fish have an electric heater so you need electricity nearby. Our last pond we used a fibre glass preformed liner.we had a cat who sat on the edge of the original pond and clawed the liner.

The quickest way to resolve this is to throw a defrosted prawn in the water. This will cause it to rapid cycle and for two weeks your levels will be all over. Buy some generic aquarium test strips from Amazon. And monitor your own levels. You also need to research nitrate/nitrite cycles to Bertrand what’s happening. Honestly I think the shop have seen you coming as chlorine from tap water evaporates with 24-48 hours

I'd bet Pets at Home would sell you the fish.

Fish do need ponds to be clean. That's why you have to have all that stuff air filters pond balls fountains otherwise they will die.

Frogs on the other hand, I am convinced mine like it the dirtier the better.

I don't put tap water in it though, only water that has come off the roof.

There's an FB group called 'Wildlife Ponds UK'... Could she be convinced to get int seeing what creatures come to the pond naturally? This would mean you can just leave the pond and creatures would come in. It's a win win- easy, costs nothing and solves the no fish problem.

A pond without fish is far more interesting. Fish make it really dirty, you'll always be fighting a losing battle with that, and they eat any interesting larvae/tadpoles etc.

I've got a wildlife pond, had it for about 3 years now. Pre formed, no pump or filter (no way to have one without it sucking in tadpoles and froglets etc) it's got a shelf for marginals, which I rinsed most of the aquatic compost off the roots and planted in clean fine gravel. That way the plants use dead leaves and frog poo for nutrients, rather than it making the water murky, and I've got a water hawthorn to give surface cover to stop it going green from sunlight.

Filled it with rainwater, top it up from the water butt if it's hot, let surrounding plants shade it in the summer so anything living in there is a bit protected from the sun and predators. Occasionally rake out some plants if it's getting a bit over full. It's teeming, crystal clear, and I've got newts which is just awesome.

I think skip the fish, we've got a small pond, there are newts, tadpoles, frogs, the birds bath in it - it looks after itself - I occasionally fish dead leaves out of it. I've got oxgenators as well. Lots of wildlife.

Fish are difficult I think.....

I just went to pets at home - goldfish going strong, very happy, zooming around, never tested the pond but it's well filtrated, sure they're happier than the diddy fish tank they were stuck in 😕

My pond seems to manage itself.

I don't think the army of frogs that live in it really care about the nitrites. Or at least they never complain.

I did dig them a new frog cave though to shield them from the cats.

Whenever I pick the paving slab up there is always a frog or two under there so they must like it.

I ignore ours..... honestly think you trying to hard. Too many chemicals. We've had dragon flies this year which is lovely

Oh dear it sounds disappointing but perhaps you were just trying too hard?
My pond is just an irregular shape lined with black liner. It's shallow at one end for wildlife. No pumps or filters.
It probably took 2 or 3 years to settle and for algae to disappear. It has lots of plants and water lilies and is full of frogs, newts and dragonflies love it. No fish though.
DS2 punctured it with a stick when he was 4 and I repaired it with duct tape.

Maybe just leave yours alone, skip the chemicals and let nature move in?

The water volume may just be lower due to the warmer weather. Top it up with a hose and monitor it.
I have a tiny pond and it needs topped up in a hot spell. Definitely no leaks.
The water balance sounds tricky. Did you speak the aquatic shop aboybthe choice and quantity of plants as some can elevate nitrate levels. Water soldier reduce nitrate levels and float in ponds quite happily.

Hope you get it settled and are able to get fish soon.