View Full Version : Wetland System Help

08-13-2008, 06:39 PM
This is kind of rare project for me that is a having a problem, it was my first wetland system and it was an above ground. The company that built the concrete block tanks did a bad job; tanks didn’t hold water. We placed liner in the tanks and solved the leak problem. The main tank that we were aiming to filter is 40’L X 7’W X 3’ 1/2 D. I designed a new tank to be built on to the far right side of the picture, the new tank was about 10’LX 4’ W X 3’ ½ D. I placed all the recommend rock sizes around the wetland system and built my own wetland system based on aquascapes wetland, then placed a variety of different plants. The pump is about 7000gph. The owner of the tanks has another system that takes all the water off the roof of the building next to the tanks and refills the tanks. This system worked great for about a month, the water was crystal clear. I get about 8 hours of sun on the tanks but I have a form of small algae floating in the whole tank from top to bottom. Does anyone have an idea on something that can be tried?

08-14-2008, 10:46 AM
My first thought is to decrease the water flow. Constructed Wetlands work more efficiently utilizing a low flow rate. What with the rock and gravel, you maybe only have 2,000-3,000 gallon water capacity in the larger tank. I would start with a 2,000 gph flow rate and adjust it as needed. You might also try more reeds and Cattails. Cattails especially are amazing in their water filtering ability. You did not say what the ultimate destination is of the filtered water. A Constructed Wetlands filter of this size could maintain a quite large water feature.

08-14-2008, 11:42 AM
Correction to my previous post-
The capacity of your Wetlands filter is more like 500 gallons. Of more importance is the surface area of the Wetlands Filter. Ideally, a Wetlands Filter should have a footprint equivalent to 30% of the feature that it is filtering. Your large tank has a footprint of 280 sq/ft which means that the Wetlands Filter should have a footprint of 84 sq/ft or 8' x 10'. Your present Wetland Filter is only 40 sq/ft. Can another Wetlands filter of the same size be installed at the opposite end of the large tank? This would give you your 30%. The flow rate should be reduced, in any case, in order to create more resident time for allowing nutrient uptake by the plants.

08-14-2008, 03:27 PM
thanks for your replay . The reason for this filtration system is to grow cat fish while using a natural system. There is a palm tree right behind the wetland , there is no room for a new tank. I will try using smaller pump. Thanks

08-14-2008, 06:56 PM
Unique Water Feature problems intrique me, so if you have time, I have a couple of questions. In the photo of the entire feature, is the upper large tank part of this system? If it is, then you will definitely require additional filtration. Also, in the same photo, there appears to be the shell of an unfinished lower half-circle pond. This could possibly be used for additional filtration or a portion of either/or both large tanks can be converted to Wetlands. Just from what I can see in the photos, it seems that you have several options available. Just passing along some thoughts.