low flow RUGF

[Matt181]

Right heres a quick break down.

i want to keep frontosa, who like low flow,
i also want to keep a clean fish tank, no crap on the bottom,
i want to use sand as a substrate, keep things natural and looking nice.

will a RUGF do this for me? i dont want to use those "jet" ones ive seen as i think this would freak out the frontosa but at the same time i want to keep crap off the bottom.

so would several lines of PVC installed under the sand with loadsa holes drilled in, give me enough flow to keep the crap off the bottom without freaking out the fronts?

i was thinking of plumbing it in as the return from my wet dry.

anyone tried a low flow version of this?
ive seen what im thinking of done before but these have had high flow rates.

Thanks
Matt

 

[LD50]

I dont think it will keep the doo doo off the bottom, esp when your fronts mature and start laying down big turds. But this isnt really a reason not to do a low flow RUGF. For one you wont have to worry about extra bio media b/c your sand will be your bio media, so in your W/D you could load up on good mech, alagae scrubber etc. Also you wont have to ever think about stiring/mixing up your sand with a RUGF.

 

[dawnmarie]

Well said. How low a flow are you proposing ? How big is your tank ?
How are you supplying water to the sump ?

 

[CHOMPERS]

I'd look into making a type of plenum with a fine mesh on top. With sand, you'll want the flow through the sand as even as possible.

 

[KaiserSousay]

Would think anything that would let flow through it would not be called sand.
Think of fluidized sand filters, the only way they work is by having the sand in suspension. If not in suspension, all it will do is blow a hole in the sand bed, even at low flow levels.
Trying to get the gunk up into the water column would require enough force for all but small grain gravel to go up with it.
Really can`t picture this working, but I have sure been wrong about other things.

 

[zennzzo]

No ...I will agree with you on this one...using the "fluidized bed filter" analogy pretty much paints the picture of the flow needed to break up the surface tension of the sand substrate. And that would include a "too low of flow" channeling as well...

If you want to keep Fronts and sand,
(which I find to be a very handsome combination btw),
you are going to have an extra bit of maintenance to keep pristine...

 

[Pharaoh]

I wouldn't necessarily do a RUGF, but you could look at doing a couple Under Gravel/Sand Jets. You could strategically place these to kick up debris in areas where it tends to settle. That might keep things a bit cleaner for you. I will be doing something similar on my setups.

 

[LD50]

Would think anything that would let flow through it would not be called sand.
Think of fluidized sand filters, the only way they work is by having the sand in suspension. If not in suspension, all it will do is blow a hole in the sand bed, even at low flow levels.
Trying to get the gunk up into the water column would require enough force for all but small grain gravel to go up with it.
Really can`t picture this working, but I have sure been wrong about other things.

Good point about the low flow blowing a hold in the sand bed I never thought about that.

I wouldn't necessarily do a RUGF, but you could look at doing a couple Under Gravel/Sand Jets. You could strategically place these to kick up debris in areas where it tends to settle. That might keep things a bit cleaner for you. I will be doing something similar on my setups.

Now that sounds choice!~

 

[CHOMPERS]

Would think anything that would let flow through it would not be called sand.
Think of fluidized sand filters, the only way they work is by having the sand in suspension. If not in suspension, all it will do is blow a hole in the sand bed, even at low flow levels.
Trying to get the gunk up into the water column would require enough force for all but small grain gravel to go up with it.
Really can`t picture this working, but I have sure been wrong about other things.

Ready for the Nerd Herd to get nerdy? The sand, although packed pretty tightly, is still 36.6% empty space (unit cell space). Sound too weird to be true? It is. The sand grains are like tiny spheres, not boxes. Spheres do not pack together completely. A room full of basket balls has tons of space between each ball, but a room full of stacked boxes has none. Here's another explanation:
http://en.wikipedia.org/wiki/Random_close_pack

As long as the flow does not exceed the space between the grains, the sand will not lift up. That is why fluidized bed filters require a large pump. That is also why I think this would require a plenum rather than pipes with holes. This will also probably need large grain sand (play sand washed in a "sand boil").

 

[zennzzo]

seems to me that by time you pump enough water to get to the surface of the sand and do so with enough velocity that it will clear debris, it will have had to disturb the underlying layers of sand.
Having no way to control an even backpressure over the entire footprint of the tank, the current will seek the path of least resistance and channel up through the sand...

maybe this is why you are saying it would need a plenum? But even with an air space it seems like sand is too easily disturbed to not channel holes...

I'll wait and see, if it could be done and done easily, I'd be all for it...