The shorter on on the left is actually another skimmer, my first attempt at a DIY skimmer.... actually works quite well most of the time, just a MJ1200 running it with a small venturi. Just seems to go bonkers every couple of months, dumps about 10 gals up to the collection cup, with a 1G jug as the final container it makes a pretty good mess, and always at the worst possible time.....