# Inline mechanical filter using sand



## Benhouse (Apr 16, 2012)

I had an idea i don't know if it makes sense but the idea is to build a filter that would polish the water . Im thinking get like a 2" pvc pipe put caps on the end drill holes in caps to allow for a smaller pipe to be attached as inlet and outlet fill the pipe with filter sand like what they sell for pools probably use cotton tshirt or similar fabric to keep sand in 2" pipe and not flow into tank my question is how fine of filtration would i see and how much this would slow down water flow the idea is to have this either on the return or drain line from the tank to or from the sump this is different from a fluidized sand bed in that it would be filled with sand vs only 1/2 full with fsb


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## Rick_Lindsey (Aug 26, 2002)

PFS is Pool FILTER Sand... but I'm not sure exactly how those filters work. A brief google search netted a few pages, it seems they're intended to trap particles in the 40-100micron range... there was talk about pressure increase by 8-10 lb as the filter got full of dirt, so it may not be as simple as taking a FBF and packing it full of sand. Armke's raved about Under-Sand-Filters ala UGF, but that will have alot more surface area than an inline sand filter.

-Rick (the armchair aquarist, who thinks it sounds neat, but has no idea how well it would work)


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## Benhouse (Apr 16, 2012)

Well riddle me this batman, what size particle would you average hob all in one cartridge filter catch


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## lucid_eye (Apr 12, 2009)

I liked the armke's setup, a standard ugf with pantyhose stretched over it and sand instead of gravel, however I am curious how well it would work when you start working on tanks larger than 20 gallons.


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## rous (Apr 10, 2006)

Just a question - would that inline filter need to be mounted vertically, with a lot of space for the sand to move with the water flowing through? If it was horizontal, it seems like the sand would all get "pushed" to one end and jammed against the outtake, creating a lot of backpressure. Definitely not an expert, but my limited experience with pool filters was that the water was kind of "bubbling up" through the sand, not traveling through a constricted canister or cylinder......
Definitely interested to hear how it works....


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## Benhouse (Apr 16, 2012)

Yes i am thinking that it would create some backpressure but that back pressure is whats creating mechincal filtering as opposed to bio if sand is fluid then impurities will just escape back into tank what im wondering is what particle size is caught by your runn of the mill filter floss and is the reduction in flow rate worth it


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## Benhouse (Apr 16, 2012)

Also the prob i see with an ugf is that there is no way to clean it that i can think of where as w cylinder you can dump out sand rinse out the sand and refill cylinder


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## lucid_eye (Apr 12, 2009)

Well that is the idea behind the sand ugf. You use the sand as a filter and the space under the ugf would not need to be cleaned. But that whole idea goes to **** as soon as a fish digs down to the ugf.


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## Benhouse (Apr 16, 2012)

Hey guys have an update i have made a prototype(i use this term loosely) i put a cotton tshirt into a cut in half2liter bottle filled with sand the flow rate at gravity pressure ie 0psi was around 15-20 gph ie way too,slow also after running water that i rinsed my filter pads into . The water was still tan so for it to run at a flow rate aceptable for a55 g yo would need an powerful pump i deem the idea impractical as a inline now does anyone have experience with using undersink /whole house sediment filter and how powerful of a pump you need to run a 10gpm water filer cause i know that 10gpm is at house pressure


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