the water level will vary depending on the skimmer type/design... if you can get it dialed in so the water is just below the tapering throat up to the collection cup without it creating way more waste water than foam that's a good place to start... from there minor adjustments should get you set. A MJ1200 may no be such a bad feed pump with the sedra recirculating water... slow flow through the skimmer with max bubble contact time is what you are looking to get get towards max efficiency, however it may be just a bit underpowered perhaps a Mag5 or similar would do better... again it depends on the skimmer... what are you using?