Why I like a Reverse Undergravel Filter

[Freenow54]

Please explain what gets contaminated with RFUG.

Both of my display tanks at 75G & 120G have been set up for 15 years with RFUG.

That is my confusion. I hate Acronyms and don't know what you mean totally by RFUG which is why I made the previous statement. See Paul's reply to me . He says running an under gravel filter with normal flow does not Contaminate the Tank ,but it will crash , yet he doesn't know why. If that isn't Contamination of some sort I don't know what is .

 

[Subsea]

That is my confusion. I hate Acronyms and don't know what you mean totally by RFUG which is why I made the previous statement. See Paul's reply to me . He says running an under gravel filter with normal flow does not Contaminate the Tank ,but it will crash , yet he doesn't know why. If that isn't Contamination of some sort I don't know what is .

Reverse Flow Undergravel Filter

Flow is pumped into the plenum and up thru the substrate. Where is the contamination?

I suspect Paul got confused with your question.

I have been running RFUG for 15 years. NO CRASH.

 

[Freenow54]

Reverse Flow Undergravel Filter

Flow is pumped into the plenum and up thru the substrate. Where is the contamination?

There is none in that case . Which is all I was trying to say in the beginning. The contamination ( me ) or Tank crash ( Paul )occurs if you run it as intended for a fresh Water Tank. that is what I thought you meant originally . This is all from Paul not me. He has talked about it at length and in one of his books . That said how do you clean yours or do you ?

 

[Subsea]

There is none in that case . Which is all I was trying to say in the beginning. The contamination ( me ) or Tank crash ( Paul )occurs if you run it as intended for a fresh Water Tank. that is what I thought you meant originally . This is all from Paul not me. He has talked about it at length and in one of his books . That said how do you clean yours or do you ?

I do not clean void under RFUG nor do I clean MULM in my refugium. I also dose ammonia as the coral & bacteria are the biofilter.

PS: I also have Paul’s book AND I have visited Paul at his home on Long Island.

 

[Freenow54]

I do not clean void under RFUG nor do I clean MULM in my refugium.

Now you are just messing with me I will bite what's MULM?

 

[Subsea]

Now you are just messing with me I will bite what's MULM?

https://www.reef2reef.com/threads/mulm-in-a-reef-tank.252780/#post-2981931

“I think one of the most important, and least understood or mentioned things in a reef tank is "mulm". That stuff that grows in the dark portions of a tank if it is set up long enough. "Mulm" is a combination of algae, sponges, bacteria, pods, worms, detritus, poop and any thing else that can be propagated or grown in the dark. I realize most people would immediately get out the sponge, razor blade or grenade to remove it but there is a word I like to use to describe those people. That word is "wrong".”

 

[Subsea]

There is none in that case . Which is all I was trying to say in the beginning. The contamination ( me ) or Tank crash ( Paul )occurs if you run it as intended for a fresh Water Tank. that is what I thought you meant originally . This is all from Paul not me. He has talked about it at length and in one of his books . That said how do you clean yours or do you ?

Initiallly undergravel filters used uplift tubes with air bubblers. Considering gravity and downward flow, detritus would be drawn deep into substrate. I ran my first marine tank more than 55 years ago using uplift tubes for 5 years with no crash, yet It was full of Cyanobacteria.

 

[Freenow54]

Initiallly undergravel filters used uplift tubes with air bubblers. Considering gravity and downward flow, detritus would be drawn deep into substrate. I ran my first marine tank more than 55 years ago using uplift tubes for 5 years with no crash, yet It was full of Cyanobacteria.

I want to install one in my new Tank but in other posts I state that I hate HOB stuff because of the looks only . My hob skimmer works great and is easy to clean. Now another member has posted a Canopy he made so now that has taken that away . Could you show me how you made yours ? I already know how Paul makes his . So I just wondered if there is a better best way to DIY or is there actually a manufacturer who makes them ?

 

[Subsea]

I want to install one in my new Tank but in other posts I state that I hate HOB stuff because of the looks only . My hob skimmer works great and is easy to clean. Now another member has posted a Canopy he made so now that has taken that away . Could you show me how you made yours ? I already know how Paul makes his . So I just wondered if there is a better best way to DIY or is there actually a manufacturer who makes them ?

While I do have HOB filters on display tanks, I assume you are asking about reverse flow:

I used egg crate laid on top of 1/2” pvc. Then run 1/2” pump line output down underneath egg crate. In my 75G display I use a canister filter output into plenum void. Lay window screen (nylon or fiberglass) then 2” of substrate.

“is there actually a manufacturer who makes them ?“

Undergravel filters are still manufactured with uplift tube for air bubbler. Then you provide a crossover adapter to allow reverse flow. I have used cannister filters and power heads to accomplish this.

 

[Paul B]

I suspect Paul got confused with your question.

I am old and confused by a lot of things.

. That said how do you clean yours or do you ?

I stir up the substrate using my DIY 5 micron power filter.

Like this:

 

[bristleworm]

Hmmmm, wish I had read this last week. I would have been REAL tempted to put an UG plate under my substrate and plumb one of the returns into it.

 

[Freenow54]

Hmmmm, wish I had read this last week. I would have been REAL tempted to put an UG plate under my substrate and plumb one of the returns into it.

You Should Someone even used their canister filter return line cool idea