Blue Life USA - 10 Micron Filter Socks Blue Life USA Sale! from 395 /per Size 4" x 14" 7" x 16" Qty. Add to Cart This item is currently on backorder but you can still purchase it now and we'll ship as soon as more become available. Blue Life USA 10 Micron Filter Socks are perfect for using phos rx. Phos RX is a popular phosphate removing media and it will work best when used with the 10 micron socks.