# Question(s) about DIY wet/dry filter.



## AU Chief (Jun 20, 2007)

I have been planning to do a DIY Wet/Dry filter for some time. The only reservations I have are in coming up with an over flow. I've seen some complaints that these only skim the surface and therefore don't do a great job of mechanical filtration. Since I first thought of a making my own wet/dry filter (about a year), I have wondered why you couldn't just use pumps to suck the water out as well as back in (other than cost obviously). This would seem like a better way to do things, since as long as you use the same pumps both ways, you're flow will be the same; you wouldn't have to worry about over flow problems if the power goes out, and you could suck water out from different levels of the tank. I'm sure there must be some reason why this isn't commonly suggested, but I just haven't seen it. Can anyone answer?


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## iceblue (Apr 27, 2004)

Lots of things have been tried with various degrees of success. Some have intake tubes with slots from top to bottom that will draw water from all strata of the water column. Others have the intake drawing from the bottom and use the return and powerheads to direct the water towards the intake.

I personally like the idea of skimmers drawing off the top and keeping the surface clear of scum. This has a big advantage over the others in maintaining air exchange and greater oxygenation. Useing a skimmer in conjunction with either powerheads or an undergravel jet system to push water over the substrate will help maintain a constant upwelling to the surface and the removal of detritus.

I'm sure others have thier own ideas but in a situation where your using a sump wet/dry combination I would prefer a clear surface as apposed to a surface where the film is just broken up.

They also make surface skimmers that can be attached to a cannister intake although I'll have to say I've never used one and can't vouch for thier effeciancy.


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## Charlutz (Mar 13, 2006)

You won't be able to effectively match the flow into and out of the tanks, even with identical pumps. Gravity, tube size, elbows all have an effect that will result in too many variables to match them. Let alone the expense of two pumps when you can just build/buy an overflow that will do the job correctly.

In my experience, the complaints about overflows not keeping the tank free of solids are not well taken. If you have fairly decent circulation in the tank and a WD setup that flows through floss or a micron pad, your tank will be clean.


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## Hoosier Tank (May 8, 2007)

There is this *skimmerless overflow* . That is the route I am taking. It doesn't rely on a second pump and should be more effective at removing "Floaters"...


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## fishyfishyfishy (Dec 24, 2005)

I think that article borders on absurdity to think that ultimately you're only filtering the top. The water in the tank is constantly circulating and mixing and will work its way just fine to the overflow. Even with saltwater tanks, protein skimmers are put in the sumps where they are perfectly effective. I took the same approach with my polishing canister filter. I polish the water right there in the sump. Works just fine and my tank is crystal clear.

The problem with the mechanical in wet/drys is that some water can bypass/flow around the mechanical filtration and work its way back to the tank. With canisters, all the water works its way through the mechanical filtration. But, then again, as that canister clogs, flow begins to slow down significantly through it. With a wet/dry, you have a constant high flow rate that does not slow down due to clogging. That alone is probably enough to make up for the difference in mechanical filtration anyway since water will pass through the filter more often.

Although canisters do provide more "suction" at the intake, you're still talking about a tiny little opening...on average about 5/8". So really, you're relying on whatever is in the vicinity of that little opening for mechanical filtration. And again, as the canister clogs that "suction" gets significantly reduced. If anything, overflow boxes are pulling water from a broader area and should therefore pull more debris in at a rate that never slows down due to clogging.

Both can benefit from additional powerheads to keep water circulating to filter debris as there are always areas that don't get great circulation. But, again the wet/dry will always due a better job because that circulation of the water is never reduced compared to a clogging canister.


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## IrkedCitizen (Apr 26, 2007)

Not to mention that detritus/debris can be sucked out during your weekly/bi-weekly water changes.

After having a sump you will want one for each of your tanks. Not only do they add more water volume to your system which makes the water parameters more stable but adds a vast area for biological media. Way more then any HOB or canister filter can hope to have. If you are that worried about detritus/debris you can always use a HOB/canister in conjunction with a wet/dry sump. You can never have too much filtration.

:thumb: :fish:


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## fishwolfe (Mar 27, 2005)

my 110 has a d.i.y sump,cannister,hob,and water polisher.i only have 3 spots in a 6' tank that really collect any debris.


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