Remote Deep Sand Bed Filter

[FishOnCampus]

I am building one tomorrow night and will post pics as I progress. FW tank, 220 gallon, 55 gallon sump
I have a few questions that hopefully you guys can help me with.

Any creatures, besides blackworms and Malaysian trumpet snails that will help the bed diffuse?
The sand will be inside of a series of 2" pipes in parallel. What should I set the flow rate to? I was thinking a few drips per second, per line

 

[FishOnCampus]

Progress from last night. Forgot to buy a few things and they didn't have valves for airline tubing Hopefully I can get this going soon and see if it actually does anything!

 

[Gill Blue]

 

[CHOMPERS]

Following along.

I haven't kept up with the latest advancements in denitrators for freshwater, however it is my understanding that they are best left to saltwater aquariums. In freshwater they typically release hydrogen sulfide, and if the sand bed is disturbed then it can release lethal amounts. For an example, the 50g filter on my pond/pool had gone anaerobic and when the system was later turned on, it killed every fish in the pond (16,000g).

If the area where you live doesn't have significant water restrictions, it would be better to use a continuous drip water changer. But for the sake of DIY and tinkering, lets see what you can make this bad boy do.

 

[FishOnCampus]

Thanks Gill? lol

Thanks for bringing up the important issue of hydrogen sulfide Chompers. I'm just experimenting here, so obviously I could be wrong, but:
By keeping the sand inside of pipes, separate from the rest of the system, a sudden release of the gas wouldn't cause harm to the system as a whole. I put elbows in the side of the sand pipes, which will drip into an aerated trough filled with activated carbon. Any gas that was not diffused into the air, left in the water, would in theory be removed before being dumped back into the main system.
This 'risk reduction' is shrinking the size of my DSB by at least an order of magnitude, so I'm not sure a significant amount of nitrate reduction will occur.

 

[FishOnCampus]

Installed and in the sump. Still need to build the trough, fill the pipes with sand/critters and buy ball valves for the airline tubing.
Pics

 

[Inglorious]

 

[CHOMPERS]

... fill the pipes with sand/critters...

Sand, yes; critters, not so much. Don't count on too much in the way for food or a habitable zone for a lot of critters. As soon as the sand runs out of O2, the critters in it will die. But other than that, I think you have a great design. I doubt that you will have to worry about hydrogen sulfide as long as water keeps trickling through it.

 

[FishOnCampus]

Each pipe is currently running at 2-3 dps. Will keep posted