https://www.ebay.co.uk/itm/20-Reverse-Osmosis-Water-Filters-Sediment-Carbon-Pole-Fed-Window-Cleaning-x6/251626189836?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649seen them on ebay and wondered are they decent to use with a twin 20" set up?