The patented bottom tray of the RAIN2 and RAIN4 is the easiest to clean of any waterfall algae scrubber. Just lift up the LED dome lid. And if you want to clean the tray in your sink, just lift the tray up too (if it's on the patented pole mount). All other box-style scrubbers require you to reach down into the box and scrape the bottom, that is, if you can fit your hand in. And if you want to take those boxes to your sink, you have to disconnect everything. Not with the RAIN... you can take the tray to the sink without disconnecting anything, or turning off the water or the lights.