A moving sand bed?

[BushFishRox]

I was just thinking of doing a moving sand bed in my new aquarium, by making a coil out of ABS, like in this crappy pic:

hooking it up to a powerhead and drilling a hole every couple of inches and capping the end, then covering that with gravel, then putting the sand bed on top of the gravel.

My hopes in doing this is to kinda make a Fluidized Bed filter. While making a kinda cool shifting sand bed.

Do you think it would be worth doing or would it be a waste of time and money. If you think it will work what would be the best diameter of piping to use and would a 1800L\h power head service?

Oh and this would be on a 220.

 

[NilePufferFanatic]

It will be tough to regulate. There will be more pressure later in the pipe, because pressure will be getting let out at the begining. Most of us have have this pressure problem with air lines that don't have regulators or gang valves (when one tube gets lower than the other(s) it quits pumping out air).

It can be done. Good luck.

 

[Toby_H]

That’s probably over 65 feet of pipe and a whole lot of 90s… it may be a little pricey…

I would imagine you could work on your pattern to be more economical and even more efficient…

I’ve found with UGJ projects that using a well balanced, symmetrical system of T’s and Y’s gives the best result… I would imagine the same principal would hold true with your application…

As an example of the balanced T’s and Y’s… here is a UGJ I drew up using the concept…

That's my two cents on how to do it... I have no clue if or how well it will work...

 

[DragonKeeper]

After a short amount of time the sand will work its way to the bottom of the tank, while the gravel rises to the top.

Keeper

 

[Oreo]

Depends on the size of the gravel & the strength of the flow. I would recommend a rather fine gravel. Something the sand won't easily sink into, but still heavy enough to separate out in the flow.

Also, perhaps consider an air-hockey table as inspiration for your design.

 

[chesterthehero]

wouldnt a steady stream of water going through sand eventually erode the sand out of the way... ?

 

[fishdance]

If you are serious about this then to keep the pressure even throughout you will need a closed loop system, not dead end pipe. The best way to maintain equal pressure is a series of parrallel pipes (ideally equal length) interconnected equally spaced apart at both ends. If your tank is long/big then 2 reverse flow powerheads mounted apart on this grid of pipes may be necessary to even out pressure differences.

Alternatively, if you are simply after the concept of a moving sand bottom then consider a false bottom glass plate accross the whole tank bottom but slightly tilted down towards the front of the tank. A series of air lifts to raise sand up from under the sheet where it will gradually slide down to the front which will be sucking the sand back under to supply the air uplifts. (The glass plate is essentially a large water lift device horizontally). If done cleverly you will not see the airlifts, just bubbling mounds of erupting sand spaced along the back of the tank. The glass plate can be sand coated and the concept is very easy, PM me if you need more clarification.

 

[BushFishRox]

thanks FD