Pond Sealant?

[adamb_94]

I am building a little pond out of styrofoam covered in hydro water stop concrete. Does anyone know of a sealer I can use that is not too expensive since I only need about 1 Gallon. I live in Canada as well.
Thanks

[adamb_94]

Jeez, this forum is no help!

[Algenco]

look into swimming pool paint