Rusty Nail

[eddie209]

I have a rectangle above ground pond(750 Gallons). When replacing the trim boards I noticed that some of the nails that hold the liner are rusty. I am using treated 4x4's with galvanized nails. Should I be concerned. Should I take off the trim and add some stainless steel nails?

 

[poconojoe]

What might be your concern? The nails will rust away and the liner will no longer be held in place or that the rust will harm the fish? I don't think there would be any concern with either of those ideas.
I would just leave it.
You mentioned galvanized nails.
I have read that galvanized products can be harmful to fish due to the zinc content. But I don't see how a few galvanized nails could even be a factor with so little material exposure.
So, it's up to you.
You could pull the nails if you like and run a bead of PL-S30 adhesive under the liner. It's a polyurethane based roofing adhesive that some members here have used with good results. It comes in tubes for use in a regular caulking gun.

 

[eddie209]

I was concerned about the nails rusting off. This pond has been for two years now. I just wanted to be sure. I am adding a bog that will sit on the edge of the pond. Once that is on, there is no moving it. The nails are above the water line. I am assuming they are getting wet from spray or rain. I think Im going to leave the nails in and put some extra deck screws on the trim.

 

[poconojoe]

Sounds good