Forevergreen,
very interesting regarding the Trex decking in shaded and humid locations....so I understand, the point you make is that the older Trex product is far from bullet-proof in constant humid climates? Also, expand a little on the plastic sono-tube thing. I have used the cardboard tubes numerous times on landlubber projects...I realize that these would only be useful as a form, then deteriorate. Do you mean to pour a concrete pier (tube) to above the water line? I envision a substantial post-hole in the bottom of the pond with a 16' long treated 6 x 6 in the middle....basically a long fence pole that projects above the water surface.
