Inherited pond

[combatwombat]

If you have lots of little holes, I'd say replace the liner and know that you're set for decades to come. Like @GBBUDD said, doesn't look like too daunting of a task. You'll need to re-home your goldfish in the meantime, though. You can get a tote and fill with existing pond water and then place an air stone in it while you swap the liners. Probably no need for filtration on the tote if you get the change done quickly.

And what an interesting filter. Plumbed with galvanized!

 

[FancyNancy]

Thank you so much for everyone’s advice… after reading what everyone has said we shall replace the liner completely.
Is it possible to put a new liner over the old one?
We’re going to look at a new pump and filter also, as this one is really confusing to us!!

 

[combatwombat]

Thank you so much for everyone’s advice… after reading what everyone has said we shall replace the liner completely.
Is it possible to put a new liner over the old one?
We’re going to look at a new pump and filter also, as this one is really confusing to us!!

You can, but you need to cut many holes in the old liner so that water doesn’t get trapped between old and new.

Your pond looks small enough to remove the old without much effort and that’s what I would do unless the old has no underlayment.

A new liner is also the perfect time to install a bog filter, which everyone here is a big fan of.

 

[GBBUDD]

Take a picture of the filter waterfall if there is one . And why it's feels confusing. I would also not just run out and buy the first liner that seems to be a good deal as they say if it seems to good to be true.

 

[poconojoe]

Thank you so much for everyone’s advice… after reading what everyone has said we shall replace the liner completely.
Is it possible to put a new liner over the old one?
We’re going to look at a new pump and filter also, as this one is really confusing to us!!

Absolutely!
Leave the old liner. Punch holes in it so water doesn't get trapped between them.

Leaving the old liner helps to keep the shape of everything. You don't want walls caving in while you switch liners.
Plus, the old liner is a form of protection for the new one. Just make sure there isn't anything puncturing and protruding through the old liner that can damage the new one. Clean it all out with a broom or shop vac. Then feel all around to make sure it's safe to lay the new liner.

 

[FancyNancy]

Much appreciated advice.
I’ve looked into the bog filters also as suggested.. they look like the way to go for sure.