When things go wrong

[thebiggerthebetter]

Plasticizers can be toxic to aquatic animals. Some types of plastic contain a lot. If the pond is doing fine, then that’s obviously not the problem. I was just wondering if the op had done anything about it and if the op did something , what?

To make our ponds, we buy liners meant for aquatic life - EDPM rubber, PVC, vinyl, etc. which are known or assumed to be benign but I'd not say that rinsing them a few times or soaking them and discarding water a few times is a bad idea. I just never done it. Maybe to my fish detriment but I've not noted.

 

[Fishman Dave]

Not sure if I ever mentioned the real original reason my pond has a double liner.
Yes - it was really handy at stopping the pacu bite through the creases in the corners, and 1” tubing used to stop him biting through the cables to the pumps, but originally I had just the single butyl liner. However after 4 days of waiting for the silicone to cure properly after building the pond and installing the viewing pane, I noticed we had inadvertently mixed up 2tubes of roof and gutter seal with the silicone.
The roof and gutter seal had “unknown baddies” in it and I couldn’t take the risk of these effecting the fish. So I bought a second liner, a pvc one and put that over (inside) the first and sealed it (with silicone) to the glass 1” inside the first. Thus covering any roof and gutter seal.

Fast forward six years and the pvc liner goes brittle and starts splitting. Now water gets between the two liners. Over the next four years more and more liner comes away round the glass (helped by the catfish that all now start using the space between the two liners as home), until now the second liner is no longer attached to the viewing pane at all.

Thankfully the roof and gutter seal has been in/ part of the pond long enough to not effect the fish OR the roof and gutter seal was the reason half the fish dropped dead and it was not the nitrates and swinging ph.
We will never know!

But it MIGHT show that trying to cover up your mistakes is never a good idea!

 

[thebiggerthebetter]

I too dislike PVC liners. My 20 mil PVC liner holds water but has been shrinking and losing flexibility over years. I only used it for the first and only time to line the 25K shower tower filter 8ftx4ftx6ft tall. It's cheaper and lighter but never again. Industry standard pond liner of the 45 mil EPDM rubber is the way to go for sure for me. Plus PVC is sensitive to sun light, unlike rubber that has a 10x-100x longer longevity under the sun.