Contemplating DIY Pond

I am thinking about building a wooden frame and lining it with pond liner to make an above ground "pond" for my lanai.

Do you think BNs could "chew" through a vinyl pond liner? Anybody here have experience with this?

I work for a water gardening/Koi business and I would suggest you consider using stone.
Wood does tend to hold humidity/moisture and can attract bugs and tends to be less stable over time. You could easily put it up in one day.
We constructed a huge one for displaying aquatic plants in one day. If you use stone and "cap" it, as to cover the liner,
it will also give you a place to display house plants. Not to mention, you could work in a small waterfall which your BN's would love !
As far as liner goes, Be sure to use what is intended for ponds. What we sell is made by
Firestone and is specifically for ponds and fish with no toxic additives (unlike roofing material and other plastics)
Most pond liner is 45 ml thick and usually is good for 20 + years , there is no way a BN or a even a full size Pleco could chew through it.
I would suggest using an underlayment (its a felt type of material) to protect the liner. Most pond stores sell this as well.
I always have small scraps of liner available for sale. People purchase the smaller odd pieces for stream beds as
well as lining whiskey barrels and other DIY water features .
I would suggest finding a pond store and see if they have any scraps available.
Hope this helps. Would love to see what you come up with. Shiela

By stones do you mean bricks of some sort? I'm trying to imagine how to build a structurally sound frame from stone, lol. I was thinking wood because it would be easier to move. Thanks for the tips though, it's very helpful!

Bricks as in, a decorative type landscaping rock. Like cinderblock, there are decorative types that people use for quickie walls and planting areas.
They easily stacked usually have a curved front, come in different colors and you can also buy the thinner cap stone in the same color.
There is also no need to cement them together. So it can be moved or even removed or added to.
The only down side is, that if you used stone to cap off your liner it needs to be neutralized
(stone that has been sittting outside in the weather for some time is usually safe) as the lime on fresh cement stone will leach into your water
and have a detrimental effect on your ph. If need be you can neutralize the lime by rinsing in muratic acid, which is usually
available and most good paint stores.
But even a nicely sealed, wood frame as a cap would look nice and you would avoid this issue altogether.