Product Support | AstralPool | Pool & Spa Solutions For detailed manuals and documentation on our Astral products, search or navigate through the Product Support library below. We aim for our products to be extremely easy to use, but it’s always useful to have our resource library by your side. CANTABRIC filter | Astralpool – Manual bleeder valve for purging air inside the filter, if necessary. – Built-in manual bleeder valve for water of 3/4″ in the sand drain plug of the filter for easier drainage without losing sand. – Sand drain: 1 1/2″ for 400-mm, 500-mm, and 600-mm diameters and 2″ for 750-mm diameter.