Planted Tank Guru
Join Date: Feb 2010
Location: Newbury Park, CA
My 8' 180 gallon tank didn't have much flow through the sump. I was concerned about that as I planned the build and devised a double vertical [improved set was even clear acrylic!] spraybar on the opposite side of the tank from the HOB overflow box. One was supplied by the sump return, about 400gph and the other by the old sump pump [rio 1700] placed directly under the HOB overflow box. Worked just fine, the horizontal pipe ran under the substrate so wasn't visible. Klutzy me would pull them up though.. I still didn't have that 10x tank volume water movement though, maybe 5x. The hairgrass near the spraybars leaned toward the bars instead of away but I got some water movement in that dead spot under the HOB overflow box. I liked the way it worked pretty well. A big tank makes it easy to hide stuff like that.
Then I happened upon my current tank, a 6' 180 gallon with a large overflow box built into one end. I was so pleased with more water movement in the 8' tank I tried to get 10x in this tank. I have all the returns coming from the same end as the drain and the flow has ended up being very strong near the surface, hits the far end of the tank and goes down and across back to the drain with all sorts of swirls in between. If I feed the fish slightly soaked flake near the middle some food always gets into the overflow box after hitting the opposite wall and traveling through some of the plants. I am using a Laguna MaxFlo 1500 for the main pump that is divided into two returns and the old Rio 2500 that powers the cerges CO2 reactor. The Brazilian pennywort and P. gayi flow gracefully in the current but the pennywort does get beat up a bit. Java fern is in the direct flow and seems to love it and looks very nice. I don't think I have 10x but sure can see an improvement over the old set up. I have open pipes for maximum flow but not the velocity you get with nozzles.
If you have one or two good sized powerheads to spare I would place them low on the same side as the overflow box with pipe placed to duplicate the current return. That way you will get more water moving low under the overflow where it is likely not moving much now and the swift current is near the top where it won't bother the plants. The ugly powerhead is low where it is easily covered up! Play with the direction the returns face, they don't have to go straight to the other side, maybe point them to the opposite corner on a diagonal. Do have them parallel to one another so they don't cancel each other out.
Your skimmer teeth look even more restrictive than the ones on my overflow box. Mine couldn't handle all the flow through the sump so I cut most of the teeth off it and now can run both pumps wide open. If you want to put the other pump in the sump you most likely will have to do the same. Reef tanks don't put much water through the sump and use lots of powerheads in the tank for water movement. That is supposed to be best for biological filtration but my sump seems to be working okay even with too much flow through.
New set ups do have more debris floating around, something to do with a mature biological filter. Why that is I don't know but it will get better. The debris gets caught because of the algae on the plants, help out the plants by removing dying leaves and wiping down and/or knocking the stuff off when you do a water change.
Last edited by Kathyy; 03-07-2013 at 06:16 AM.
Reason: Back at the computer after finishing the water change!