I just finished my most of my plumbing from parts I acquired several years ago at a local Koi store so I'm still learning as I go. I'm already thinking about swapping out the HydroSieve and/or adding a "real" Sieve after it. My current setup is a concrete pad above ground for equipment and the BD is 4" gravity to the HydroSieve then I have a 3" line to the pump. I was thinking about a Zakki Sieve JR. I'm also wondering if a traditional gravity Sieve like a Cetus could be installed in ground in place of my HydroSieve? The most difficult option would be to demo my new pad and dig a pit to get down to the pond level and do a gravity Sieve in the pit. I was hoping to keep the cost around $1500 ish. Is the Zakki Sieve the only one on the market that can be above the pond level? Also is it common to just use the Sieve on the BD circuit and not on the Skimmer circuit? The Cetus and Zakki JR both limit me to 4500 GPH and I'm using a Performance Pro 1/3 6300 GPH pump. I'm concerned that if I run everything through the Zakki JR or Cetus I won't have enough flow to my TPR and Waterfall.