I'll put up a diagram below so you can see what I'm on about. Ideally, what I'm trying to achieve is more or less the same volume/flow rate leaving the tank under gravity as enters it under pressure from the 8000 lph pump from the drum (obviously taking into account that there's going to be some pressure lost through friction/head loss as the water is pumped through the convoluted pipe-run options (heater/no heater) before it gets to the AFS tank. However, my concern really is just about ensuring that the 2" gravity fed return from the the AFS tank will have enough pressure after it's been tee'd into the existing 1.5" outlet to get a decent flow back into the pond. I do intend to fit a couple of ball valves before and after AFS tank (but not shown on the diagram) in order to regulate the flow in and out as required as that will also enable me to isolate the AFS and, following relocation of the biocenosis baskets back into the main pond, it will then become my QT (has a separate/independent filter setup for that).
My very basic and crude experiments of pouring a 2l jug of water into a 1.5" pipe from about 36cm seemed to take about a second - no more than 2 - as near as I could tell which makes me hopeful, but I was wondering if any of you guys knew of a rule of thumb or an equation to calculate if I'm onto a winner or am I in danger of emptying my pond and flooding the garage floor?
Thanks and regards as always, Mick
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