I am thinking of making a goldfish pond in my yard, beneath three large pine trees, but I'm worried that the falling needles may be toxic for the fish.
Are pine tree needles toxic for goldfish ponds?
I have never heard of toxicity problems, but they could cause a downward pH shift over time.
To combat that, you could try running the water from your circulation pump through some crushed coral. If the water is too acidic, it will dissolve minute amounts of the coral which will buffer the water a bit and help keep the pH more stable.
Not sure what you have in mind for structure, but maybe you could incorporate something that would cover part or all of the pond and prevent some of the needles from getting in. That would also provide shade - maybe not a factor where you live tho, I don't know. (Where I live, if a pond isn't fairly deep it will get overly hot in the summer - so shade is a consideration)
A covering may also help protect the fish from predators - again, may be different where you live, but I had a heck of a time keeping Egrets from using my pond as a buffet.
Reply:Hi While they are not toxic I would strongly suggest not building a pond anywhere near a pine tree unless you have a suitably sized netting to prevent any falling in. The needles %26amp; cones fallen form the tree are a very real danger to the fish as they will almost certainly get them stuck in their throat %26amp; gills which is fatal if not removed. Check any moderated pond forum or site for confirmation of this hazard-it's far more common that many people realise.
Reply:don't build it under any type of tree, it will work you to death trying to keep the leaves out, believe me