Opinions on Plenums

[livebait]

I'm having a tough time deciding how I want to build the floor of my upcoming macro/h.fuscus tank. I understand the principal but are they helpful or a hazard? Please share your experience with using this system if you have any. Since this will only be my 2nd build your opinions and input are greatly valued!

 

[Clownfish518]

I have used plenums and DSBs for almost 20 years. I cannot quantify a difference that a plenum makes over a DSB, so I stopped using them 10 years ago or so.

After reading Dr. Ron Shimeks (invertebrate zoologist and hobbyist) writeups on DSBs, if Shimek is correct than the underlying theory behind plenums is suspect. Shimek writes that it is the movement of the micro fauna through the sandbed that is the prime cause of water movement through the sand.

Also writes that hermits will eradicate much of the microfauna in the first inch or so of the sand bed and should excluded from a tank with a DSB. I have also have that same information from Eric Borneman and Chuck Rabbe in personal communications; when so many experts agree, I listen.

A better option IME is a remote DSB; either in the fuge or somewhere in the sump system. Much easier to keep clean. Calfo writes that a 5 gallon bucket is all the sand require for a 180 gallon tank. It does not take a lot of sand to reach maximum filtration capacity. I only do DSBs these days in tanks where the inhabitants need it (like say a BSJ)

my 2 cents

 

[Eric]

Clownfish, how do you set these remote sand beds up? I mean are they set up like a sand bed filter where the water passed through the sand or do it just pass over like in the tank?

Thanks

 

[Clownfish518]

Just pass over like in a tank. If you can get 8-10" deep in a bucket that is great; and if it is not lit then it is very easy to keep clean.

 

[Clownfish518]

New acronym - RDSB

 

[Eric]

Sorry to hijack livebait, once more string of questions.

How much flow for a RDSB, how does it keep from getting impacted, how long will it last? I know that last question has a lot of variables.

Where can I find more info, I have liked this idea since I seen you mention it a while back.

 

[livebait]

I have used plenums and DSBs for almost 20 years. I cannot quantify a difference that a plenum makes over a DSB, so I stopped using them 10 years ago or so.

After reading Dr. Ron Shimeks (invertebrate zoologist and hobbyist) writeups on DSBs, if Shimek is correct than the underlying theory behind plenums is suspect. Shimek writes that it is the movement of the micro fauna through the sandbed that is the prime cause of water movement through the sand.

Also writes that hermits will eradicate much of the microfauna in the first inch or so of the sand bed and should excluded from a tank with a DSB. I have also have that same information from Eric Borneman and Chuck Rabbe in personal communications; when so many experts agree, I listen.

A better option IME is a remote DSB; either in the fuge or somewhere in the sump system. Much easier to keep clean. Calfo writes that a 5 gallon bucket is all the sand require for a 180 gallon tank. It does not take a lot of sand to reach maximum filtration capacity. I only do DSBs these days in tanks where the inhabitants need it (like say a BSJ)

my 2 cents

I also considered a remote dsb. Read something you had written before and did a bit of research on them. The tank will be in the living room so a 5 gallon bucket is out of the question but since I'm building the cabinet I could easily work in a deep fuge next to the sump.

 

[BigAl07]

I'm probably going to attempt a RDSB in my next set-up. I'll either have a SSB or BB.

 

[Clownfish518]

Sorry to hijack livebait, once more string of questions.

How much flow for a RDSB, how does it keep from getting impacted, how long will it last? I know that last question has a lot of variables.

Where can I find more info, I have liked this idea since I seen you mention it a while back.

Coral Magazine, Volme 4, Issue 5, Sand Bed Filters is a good place to start. Unfortunately, its not online.

Here is a good online article

DSB article - CALFO

The answer to your question is, keep it flowing!

 

[Eric]

That CF I found that after I posted along with enough info and opinions to confuses A. Einstein lol

 

[Clownfish518]

That CF I found that after I posted along with enough info and opinions to confuses A. Einstein lol

LOL

I am a geek sometimes with this stuff

the Coral magazine articles are really good.

 

[BigAl07]

That CF I found that after I posted along with enough info and opinions to confuses A. Einstein lol

Well in that case I'm

 

[DaveK]

I would agree with clownfish518's post about the use of plenums. They seem to be of questionable value.

As for the experts -

It can pay to listen to them. They often offer good advice. However, it is often the world as seen by that expert. Therefore, never take anything they say as gospel, even if they are in agreement. Remember, they read each others books and articles too. Bottom line is that many times they may know less about the subject than you do. Trust but verify.

Also keep in mind that most of our knowledge about SW aquarium systems did not come from any type of controlled scientific testing, but rather were the result of someone trying something different based upon their own personal hypothesis. The if the idea seemed to work, or at least work better that what was before, it became widely adopted.

Lastly, if you are going to try something very different from the mainstream, make sure you have a valid reason for doing so. no point in risking expensive livestock with out some big potential gain.

 

[BigAl07]

Very good post there DaveK!

I also suggest a couple of points (From personal experience):

1. Know WHY your changing and what possible adverse effects are possible. The more you understand WHY the more prepared you are to make intelligent decisions on what to do.
   
2. Have a game-plan from the beginning and don't just "do it" especially if it's a big change. I like to have something on paper before hand if possible. I've caught more than one over-sight once it was on paper and more "tangible".
   
3. Have some options/ideas of what to do if it doesn't "work" as you planned or had heard. Have an OUT if possible. I like to be able to "segregate" the test system if possible (valves & gates to turn Fuge/Sump OFF if I run into an issue). I've actually had to UTILIZE this not long ago when I had an issue in my fuge....
   
4. If possible don't "Test" theories on your beloved and most prized tank/system. If something has to "Crash" I'd rather it be one of my smaller systems than my main system which might take years to re-build. This may not always be a viable option for some of us but if you can don't test your "Baby"

 

[Clownfish518]

Very good post there DaveK!

I also suggest a couple of points (From personal experience):

1. Know WHY your changing and what possible adverse effects are possible. The more you understand WHY the more prepared you are to make intelligent decisions on what to do.
   
2. Have a game-plan from the beginning and don't just "do it" especially if it's a big change. I like to have something on paper before hand if possible. I've caught more than one over-sight once it was on paper and more "tangible".
   
3. Have some options/ideas of what to do if it doesn't "work" as you planned or had heard. Have an OUT if possible. I like to be able to "segregate" the test system if possible (valves & gates to turn Fuge/Sump OFF if I run into an issue). I've actually had to UTILIZE this not long ago when I had an issue in my fuge....
   
4. If possible don't "Test" theories on your beloved and most prized tank/system. If something has to "Crash" I'd rather it be one of my smaller systems than my main system which might take years to re-build. This may not always be a viable option for some of us but if you can don't test your "Baby"

I agree. My 30 is more or less a test system for removing intakes from tanks, using a gravity fed refugium, and LED lights. So when I build out my 120 which is sitting in the garage, I get it done right. I almost typed so there are no surprises, but there always are some things that just don't go as planned.

 

[livebait]

Thanks to CF for giving me information I could actually use to help with my decision.

 

[BigAl07]

Careful how you word things.. .you might burn some bridges for future questions

 

[Eric]

That stings lol