HOB placement

[Abiduwhabi]

Hello all,

I have done a little research but have been getting some mix opinions and I'm not even for sure if it matters.

I have two Aquaclear 70's on the back of my 55 gallon tank. I have it line up as so.

____X_______X____

They are in the middle of each side. Now what I have noticed is that this creates sort of a whirl pool effect and all of the poo on the sand and the duckweed on the surface get sent to the back middle of the tank.

Should I leave them as is, grab a powerhead and point it toward the middle of the tank to get rid of this dead spot, or is there another way I should have my filters situated to prevent this.

Some people have suggested

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I thought that the one with the HOBs on the sides was ingenius, of course it doesn't really help the looks of the tank very much.

 

[wildroseofky]

Try moving them a little closer together. It seems to me, anywhere you place an HOB you get a dead spot. I just added a power head to keep things moving. I am planning on adding a second one to my tank. It will be interesting to see what people suggest.

 

[Fresh2o]

I have two AC50s in a 20g long (yeah, a bit much) and I first had it like this:

__X_______X__

But the one on the left was too close to some dwarf sag (keep sucking up leaves in the intake) so I changed it to this:

______X___X__

You would think that there would be an accumulation of waste in the left corner but there is not for some reason. BTW I use waste (plant debris, fish poo, etc) to help determine water flow pattern. The tank has quite a few plants in it and debris tends to accumulate only along the back wall. Since the turnover is about 20x, I'm not too concerned about dead spots since this is a primarily a planted tank with some fish present (7 longfin danios + 4 gold tetras).

Ideally I would want an HOB at each end of the tank facing each other but off set enough so that a swirl pattern would occur at the surface. Due to the lighting setup this canny be done.

I agree with the other post about adding a powerhead to remove any dead spots.

 

[Abiduwhabi]

Hmm I might have to try that setup. My only concern with that is my back wall is covered in plants, might make it hard to vacuum, I'll see though.

Either way a powerhead is in my forcible future.

 

[Fresh2o]

My only concern with that is my back wall is covered in plants, might make it hard to vacuum, I'll see though.
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I have not vacuumed the tank in almost a year! I do stir up the muck from time to time and let the HOB filters catch whatever is suspended. During water changes I place the hose near the surface and remove most of the debris on the bottom, especially in the back and hard to reach areas.