Reverse under gravel filter

[Kershaw]

I’m setting up a new tank. My tank has internal bracing so there is 1/2” step down that I would like to make a Reverse under gravel filter.
My design is to use 1/4 thick star board with 1/4 channel down to make the bottom of tank flush. Drill small holes every square inch. Then use two small sicce pumps to push water down into Channel to cause water to come out of holes and through sand. Here is a picture of my idea.

will this work?

 

[blaxsun]

For saltwater? No, I would't suggest this.

 

[BiggestE22]

I’m setting up a new tank. My tank has internal bracing so there is 1/2” step down that I would like to make a Reverse under gravel filter.
My design is to use 1/4 thick star board with 1/4 channel down to make the bottom of tank flush. Drill small holes every square inch. Then use two small sicce pumps to push water down into Channel to cause water to come out of holes and through sand. Here is a picture of my idea.

will this work?

Throwback for real. No reason for this. 2 options bare bottom or sand.

 

[Eagle_Steve]

I’m setting up a new tank. My tank has internal bracing so there is 1/2” step down that I would like to make a Reverse under gravel filter.
My design is to use 1/4 thick star board with 1/4 channel down to make the bottom of tank flush. Drill small holes every square inch. Then use two small sicce pumps to push water down into Channel to cause water to come out of holes and through sand. Here is a picture of my idea.

will this work?

@Paul B should be able to chime in on RUGF setup and if it will work or not. HIs tank has been running that setup for years.

 

[Kershaw]

For saltwater? No, I would't suggest this.

Any reason why wouldn’t suggest?

 

[N.Sreefer]

Will it work? Yes it can. Not many people doing it that way anymore but it still works just as well as it used to. It works best with crushed coral or dolomite you may run into issues with sand.

 

[Kershaw]

My question is targeted at will it function properly or not. Not if it has a Benefit or not. If it does it provides no benefit I can just turn off pumps. But if the design won’t work then I won’t waste my time

 

[BiggestE22]

Any reason why wouldn’t suggest?

What are you trying to accomplish by going with an under gravel filter? What appeals you to this filter?

 

[Kershaw]

What are you trying to accomplish by going with an under gravel filter? What appeals you to this filter?

I feel that the design will help keep sand cleaner by pushing some of the crud up. And prevent stagnant chemicals from building up. I won’t run bare bottom as I intend to have wrasses.

 

[BiggestE22]

I feel that the design will help keep sand cleaner by pushing some of the crud up. And prevent stagnant chemicals from building up. I won’t run bare bottom as I intend to have wrasses.

Ok I see. Do you oppose simply cleaning the sand periodically to keep it clean. As far as issues with sulfur oxide etc you could limit sand height to 1-2 inches. You would likely only have those concerns with a deep sand bed which would be 3-5 inches.

 

[BiggestE22]

I have the higher priced python but prefer using this with a 5 gallon bucket

 

[Tcook]

I ran this in the early 80s and it was OK. I think most people run a 1-2" deep sand bed so I don't think this would be necessary. You cuc (nassarius, conch) will keep it plenty clean. I don't see this pushing anything up in a deep bed. The fines will settle at a deeper depth and not be pushed up and out. jmo.

 

[Dan_P]

I’m setting up a new tank. My tank has internal bracing so there is 1/2” step down that I would like to make a Reverse under gravel filter.
My design is to use 1/4 thick star board with 1/4 channel down to make the bottom of tank flush. Drill small holes every square inch. Then use two small sicce pumps to push water down into Channel to cause water to come out of holes and through sand. Here is a picture of my idea.

will this work?

@Lasse any ideas about this? @Paul B any words of wisdom?

 

[Kershaw]

Ok I see. Do you oppose simply cleaning the sand periodically to keep it clean. As far as issues with sulfur oxide etc you could limit sand height to 1-2 inches. You would likely only have those concerns with a deep sand bed which would be 3-5 inches.

Just wanted to try something new to me. I completely understand it may have zero Benefit. But if it does have a benefit it will be allot easier to do now before I fill it. I do only plan to run 2-3” sand bed.

 

[jsker]

This thread might answer a few of your questions Lasse build thread

 

[FishTruck]

I think it is a great idea - so long as you regularly stir and clean your sandbed and sponge filter the water so that food does not get pushed under the plates.

Check out Paul Bs threads and his book on the topic (page 79).

I am unsure about the raceway idea. In Paul's book, he uses a manifold to direct the water into the RUG plates right, left, and center. I guess... one per plate. He filters then incoming water with sponge filters and the flow is pretty slow 150 gph per tube - which he describes as pretty slow. He also uses dolomite, but, states that he thinks crushed coral would work. I would recommend dolomite due to crushed coral pebbles dissolving and shrinking into sand over time.

 

[TCoach]

As others have mentions, @Paul B runs one in his main display and @Lasse runs one in his refugium. Both have good information in their build thread(s).

Given their long term success with their tanks, I'm seriously considering one if I ever upgrade my tank. The RUGF seems to be a great space for cryptic organisms and sponges. Lasse also pumps skimmate down his to help with developing anaerobic conditions.

 

[Kershaw]

I’ll wait for the two guys that use them to chime in before I decide how to move forward. I really would rather use real sand over dolomite or crushed coral. So it sounds like I might just cancel this idea. But I’ll wait and see what they say. Thanks everyone for the input

 

[snorklr]

only thing i have to add is that every commercial undergravel i've ever seen is just a big open plenum and not set up as a maze like your design...and you basically need space between the grains for water to flow and slots/holes in the floor have to be smaller than those grains or everything will just pour through...so normally gravel instead of sand

 

[Kershaw]

only thing i have to add is that every commercial undergravel i've ever seen is just a big open plenum and not set up as a maze like your design...and you basically need space between the grains for water to flow and slots/holes in the floor have to be smaller than those grains or everything will just pour through

The purpose of the maze is to support the weight of sand and rock while creating a cavity for the water. Hole size would be based on size of sand I get.