Could use some opinions here.
I thought I'd add a PVC sheet to line the inside of the pond. Before I make brackets, attach a second sheet to get it to the height of the pond, and get it fixed into place, I wanted to see if you think the positives outweigh the negatives of this addition.
First, the positives:
Protection of the main liner (eliminates potential for bite damage from fish such as triggers and parrotfish).
Increases efficiency of the gyre (no folds or creases in the liner to slow water flow)
Aesthetics (looks a lot cleaner/brighter than just the black liner)
Negatives, well... one negative that I can think of off hand, but it's a big one IMO.
Water trapped between the PVC sheet and black liner. This could cause stagnation issues both short and long term. There won't be a lot of trapped water, but there is no way to avoid it with the creases in the liner.
Here is a pic so you can get an idea of what I'm trying to do. Please excuse the recent diatom bloom and cloudy water. I had just moved the rocks around to hold the PVC sheet in place (temporary - Rock will be removed once I make brackets if I decide to keep it), and stirred the sand bed quite a bit while doing so. Also, a second sheet would be glued to the back of the first, bringing it to the level of the pond.
I am leaning toward pulling it and coming up with another idea but wanted to get your thoughts before I go either way.
Thanks!