I understand you are looking ...

I understand you are looking for a screen. BUT! Upon researching the elements of pumicite it was found to be extremely high on the natural fertilizer scale. Primary ingredient is silica. It is part of basaltic compound formed during volcanic explosions. Post explosion large sheets/islands of pumice float on the ocean. Plants and especially trees will grow mainly because of the sea salt content but also because of the 90% porosity.  To buy this rich of a fertilizer would cost at least $100 for a 10 # bag. Since you already have in a liquid form. use it, store it, sell it. You can even begin your own community garden or donate it to a garden. Grow food and donate to local food banks.  Just an environmental and cost effective thought.  Good luck.