I recently purchased a used IM 112 Lagoon which is an upgrade from my 60 gallon cube with all HOB equipment. Having a tank with a sump is brand new to me and I’m nearly all finished with the plumbing, just unsure on the drains. I’ve ordered a Reef Factory medium fleece roller and plan to plumb the main drain to it. My question is, do the back-up & emergency drains constantly drain water into the sump as well? Or just if there is an issue with the main drain?