On Feb 24, 9:17*am, "john hamilton" wrote:
I want to make a tray to contain a thin layer gravel that will lift out of
an acquarium.

I thought I would use a plastic box lid cut down to size and with square
section strips of wood screwed to each of the edges to form a lip to keep
the gravel contained.

Since the wood will permanently be under water ( that's fresh not salt
water) would ordinary pine be alright to use (since this is what I have
already), or would I be best getting some kind of hard wood edging to make
this tray more durable over the long term? *Thanks for advice.

Wood shouldn't be a complete disaster, since boats and
whiskey barrels are made from the stuff, and are meant to
stay submerged continuously, for years at a stretch.
Sanitizing would be the only conceivable problem. Couldn't
you frame out the tray with yellow, drinking water grade
CPVC pipe?