pond shield over painted wood

[newbtort]

I'm in the process of making an outdoor enclosure for my rt. It will be like a tortoise table but on the ground. It needs a bottom plywood because the cement is uneven. It will then be covered with a plastic greenhouse to maintain temp/humidity. It will also have a "doggy door" pvc flaps to access the rest of the outdoor enclosure (fenced part of the garden).

I'm using the pressure treated and kiln-dried plywood to build the tortoise "table". We painted it already with two coats of exterior acrylic latex paint (Glidden Premium). I was going to use a pond liner.

But after going back to the forum, I just learned about Pond Shield.

So a few questions:
1) Can I still use Pond Shield on painted wood?
2) If so, do I paint inside and out?
3) If I can still use Pond Shield, Should I still use a pond liner? Or is that overkill?


Thanks!