Hello fellow hobbyists! I appreciate any input, advice, comments, critiques, etc. on this topic. I really need some help on this. What filter and equipment do I put inside my sump? And inside which chamber? My objective is to reduce nitrates. Every other measurement (ammonia, nitrite, phosphate, etc. is good). BUT, my nitrates are through the room at 80ppm. Yes, I know water change will help. However, what about my sump's arrangement and filter media and equipment used? here is a description of my sump and what filter media and equipment I currently have inside. Sump description: 5 chamber sump. Each chamber is about 18'' x 8''. Two drainage pipes from overflow and both drain about the same amount of water each. One pipe drains to the 1st chamber on the far left. The second pipe drains to the 5th chamber on the far right. Return pump returns water in the 3rd chamber (the middle chamber). Reef tank: 8 weeks old (very new tank) 187 gallons with one overflow that has 2 pipes for drainage. 4 x 150W lights + 4 x 65W T5s + Moonlight LEDs + 3 x Koralia 1400 GPH powerheads 1 1/2 inch to 2 inch deep sandbed. Only 70 lbs of live rock ( I don't want to add anymore. I prefer more room for corals and fish to swim) About 10 fishes, with a combined length of 24 inches. 10 corals (mostly softies and 3 hard corals) 1 sea anemone bubble tip 2 cleaner shrimps, some snails, crabs, one slug Sump Equipment: Pump: Eheim 1260 (measured at about 500GPH returning to my tank) Equipment: 2 Tunze 9006 classic skimmers UV Sterlizer Coralife Turbo twist 18x (with a small pump) Nextreef SMR1 reactor with vertex bio pellets (with a small pump) Sump Filter media: 4L of Seachem matrix (I don't have mesh bags for them. I just threw them into the sump chambers without mesh bags. The matrix simply sinks to near the bottom of the sump chambers where there are filter wool above filter grids). I just put in the matrix about 2 weeks ago. Maybe, the nitrifying bacteria isn't cultured enough yet. 8 bags of Seachem purigen - I heard this type of media does not remove nitrate. It removes organics and other things that create nitrate. 2 large slabs Filter wool that fits the 1st chamber and 5th chamber perfectly 2 nylon filter socks 6 bags of Bio-Chem Zorb 2 bags of activated carbon (4'' x 6'') 750ml I think... of vertex bio pellets in the nextreef reactor What filter and equipment do I put inside my sump aside from what I already have? And inside which chamber? So, how do I arrange all these filter media and equipment so I achieve the best possible water returning to my tank? Do I wait a little longer for bacteria to get cultured in the seachem matrix? Or, get more seachem matrix? Or get chaeto? Or, create a refugium to grow chaeto? I thank you all for your time in responding. It is much appreciated!