# to shorten the intake tube or not?



## thaerin (Dec 12, 2004)

For my main filtration, I've got a penguin 170 biowheel. Problem is it's only a 20 Long tank, so it's fairly short. The bottom of the intake strainer rest about an inch off the top of the gravel. I'm going to be adding a hollowed out sponge over the intake strainer as I've got lots of fry and srimp right now. Besides, any sort of plant leaf that comes off gets stuck in the intake and really reduces flow rate. Hoping the sponge doesn't cut it down to much either.
Anyway, should I shorten the intake tube? Maybe cut it so the intake ends about halfway down the tank?


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## glenhead (Jan 29, 2005)

It'll be interesting to see the votes on this. I have a 55, with an Emperor 400 on it, and I extended the intake to stop about where you're talking about. I wanted to get a bit more efficient water turnover, and figured that pulling it from the bottom and returning it to the top would accomplish that. Don't have shrimp, but the fry that were thrown early on didn't have any problem staying in the floaties at the other end of the tank.


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## travdawg (Mar 3, 2005)

Heck, with my HOB, if I could run the intake from the bottom of the tank, on the opposite side, I would. I figure the farther away from the water circulating back into the system, the better.


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## titan97 (Feb 14, 2005)

For maximum filter efficiency, you will want your intake and exhaust at opposite sides of the tank. The intake should be as close to the bottom as possible, in one corner of the tank. The exhaust should (ideally) be place on the surface or just below it on the opposite corner of the tank. I know this isn't very feasible with HOB filters, but trying to make it as close to this as possible will turn over the water in your tank faster and more uniformily.

-Dustin


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## thaerin (Dec 12, 2004)

hmmm...I could use an elbow joint and extend the intake tube towards the other side of the tank. It'd be along the bottom so it'd be nicely hidden. What would this do to the filter's performance though? WOuld having to draw the water from farther away put more strain on the motor and/or reduce the flow rate?
Not that this should be to much of a worry for me. A Penguin 170 is rated for 170 gph and a 50 gallon tank, and it's on a 20 gallon  I didn't think i was getting enough water movement at the far side of the tank anyway though so I added an Aquaclear powerhead with the quickfilter attachment to the opposite corner of the tank.


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## Bert H (Mar 2, 2004)

FWIW, on my AC mini I cut off the pointed tip of the intake and cut a small sponge plug to put in it so the baby shrimp and fry wouldn't get sucked in. Every 2 weeks I need to clean it out though, because it clogs pretty quickly.


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## gsander (Dec 18, 2004)

*??? T ???*

Maybe you could use a T at the bottome of the intake tube extended to the back mid or full corners of the tank, thus allowing water to be drawn in from both sides of the tank.


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## titan97 (Feb 14, 2005)

The longer and smaller the intake tube is, the less flow you will draw. Most people like 3 to 5 turnovers per hour, so on your 20 gallon tank, you'd need 60 to 100 gph. 170gph will work very well, unless it generates too much turbulence. Adding a sponge pre-filter will only reduce the water flow. The size and porosity of the sponge will determine just how much loss there is. I don't see any problem with the impeller breaking. As long as you have a good amount of flow around it to cool it, you should have no problems.

-Dustin


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## thaerin (Dec 12, 2004)

planning on using an aquaclear foam insert as the sponge, hollowed out to fit the strainer. Seems to have fiarly large pores, shoudl work well for a pre filter i think.


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