Reply to thread

Message: [QUOTE="Meyer Jordan, post: 308051, member: 7131"] One major item to consider here is that a fish tank and grow tanks of equal size will not have the same capacity in water. Depending on the substrate (if a gravel system is used) the capacity for water in the grow tank will only be 30% - 40% of total size. Here is one of the sources for the quoted recommended flow rate of 5 - 10 gpm.-- 5 gpm: [URL]http://www.friendlyaquaponics.com/2015/08/02/water-pumps-and-flow-rate-in-the-vegetable-troughs/[/URL] And this from the FAO: The flow rate of the water entering each canal is relatively low. Generally, every canal has 1–4 hours of retention time. Retention time is a similar concept to turnover rate, and refers to the amount of time it takes to replace all the water in a container. For example, if the water volume of one canal is 600 litres and the flow rate of water entering the container is 300 litres/h, the retention time would be 2 hours (600 litres ÷ 300 litres/h). Deep Water Culture Aquaponic Unit – Step by Step Description FAO If the system utilizes towers, then the flow rate is 2 gph/tower. [URL]http://blog.brightagrotech.com/pumps-for-aquaponics-or-hydroponics/[/URL] On the Wikipedia Aquaponic page there is a diagram of a fairly large system. A little figuring using the date provided on this chart results in a retention time of almost 5 hours. Also it should be noted that in aquaponic systems where the flow rate required for the fish tank size exceeds the flow rate desired for the grow tank, water is diverted away from the grow tank and returned directly to the fish tank. All data involving flow rates in reference to the nutrient uptake efficiency of plants, whether from engineered wetlands or aquaponics, indicate low flow rates and ample retention time. I feel that it is time to give this poor horse a break and quit beating it looking for answers that just aren't there. [/QUOTE]

Verification