posted 6 years ago
Microplastics are problematic. You can use a fine sand filter complete with an activated charcoal layer and you might still find microplastics.
I can virtually guarantee that if they're in there, you'll have a hell of a time separating them out in any meaningful way.
For sea salt, I'd give it a pass.
If you were using the sea water to amend the minerals in your soil, I would first mulch and encourage soil life to thrive, and then I would add oyster mushroom slurry. I would reapply monthly, and after you get some idea that they've established, it should be safe to apply. The oyster mushrooms should break down the microplastics into constituent molecules and trace elements and spread them to where they're actually useful.
-CK
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein