Finally cleared out the front pond (fibreglass) and got rid of all of my daughter's gambusia in the process.
Worked out its volume is somewhere close to 900 litres.
Substrate of sand and left over ADA Amazonia after the Ammo spike from the autumn.
Pond used to grow Vallis, Bacopa, Foxtail, to go in my tropical display tank and planted cichlid tank indoors.
As well as to soak a combination of driftwood and limestone for use/sale.
So water mostly quite hard and often heavy with tannin.
Some ramshorn snails, dragonfly larvae... no mosquito larvae (yet) but the wrigglers will come soon, just as it warms up. Frequent debris from Camphor pylorrus tree means there's always some disintegrating vegetable soup in the bottom.
Water circulation via 300L/Hr pump feeding fountain, no filtration other than the sponge in front of the pump impeller.
Water pH around 7.2. Temperature up to 33 in summer, down to 5 in winter.
And occasionally the dog goes into the pond cos (a) the gate to the pool is closed; and ( she likes help me aquascaping.
So what cheap, low cost, environmentally friendly SMALL fish can I put in to survive the weather extremes and other issues?
... Guppies didn't survive the cold.
... Goldfish didn't survive my cat having his friends over for "training seminars" ... "see, if you sit next to the pond, you can splish the water and these orange and black things come up and go GLOOP GLOOP GLOOP at the air, then you try and hit them on the head; it's 2 points if you hit them and 10 points if you hit them hard enuff they stop swimming and start floating. But don't eat them cos they taste horrible" ..... or at least that's what I think "Miaow, Miaow, Miaow".
... thinking some sort of perch?
Suggestions please.