Quick question for any customers using one of Bud's ATS units, or Bud if you have received feedback regarding this (positive or negative). What has been the experience of going sump-less when adding an ATS? Reason being, I'm looking to add an L2 unit to my 90g cube rimless for 2 reasons - first, for nutrient export, and second as a food source (pods) for the inhabitants. I would prefer to run a top of tank mounting system for simplicity sake (pods drop right in and minimal plumbing needed) and avoid the whole needing to run a sump for a few reasons (trying to be green - less use of electricity since no need for a return pump running, if ATS does it's job I see chaeto or other macro as an unnecessary maintenance item, and a cleaner look without supply/return lines running to/from the sump). I've seen a couple pics of customer tanks running the unit right on top of the tank, and a couple with shelf mounted which I would prefer to avoid as well. Using a custom made acrylic shelf to mount it, the footprint of the L2 would fit perfect in one of the rear corners as I'm using a dual OR Arctic S-026 units over a 36x32" tank. I don't see the L2 unit as blocking any significant light to the corner it gets mounted in since my LED units throw light sideways pretty good, and even it if did I have plenty of low light corals that could call that area home. I'm currently utilizing a PWS schedule, HOB CPR Aquafuge with chaeto and HOB skimmer which keeps everything in check just fine, but I'd prefer to drop the HOB units over time and go PWS/ATS only to really clean things up look-wise. I could drill the tank (acrylic) for a sump, but that creates a very unpleasing look to the back of the tank to me, and if it's not a necessity then I'd prefer to avoid it. So - what's anyones real world experiences with going "sans sump" on a reef tank while relying on a Turbo's Aquatic ATS unit and PWS schedule to "run the show" in terms of nutrient control? Thanks in advance!!