Plenum or DSB?

[WLSS]

I know this topic has been 'debated' many many many times, but I am still confused as to which is best to adapt.

I went to a LFS last week, wanting to buy #0 and #1 sand, to make a DSB. The guy there strongly advised me to go for plenum setup, citing his own experience as a good example, that plenum is better than DSB. I already have a problem with my cycled tank (coral chips as substrate, and thus(?), persistently high NO3) and am trying to rectify this. So, I just hope to make a wiser choice this time, to adapt the right setup. I have read some articles on plenum setup, but would hope to hear from those with experience. BTW, for a plenum setup, lest (or none) LR is required, but I thought it would be benefical to keep LR in the tank. Right?

[Black]

My opinion. Do what u hv confident in. Both are as good. I am also in the midst of my setup and was comtemplating the 2. I choose DSB becos I m more confident in this setup then having half sure in plenum setup. I also find that it is easier to find people with DSB than plenum... if I hv problem. Anyway, I love to have many LR in my tank. DSB is not a total failure (though heard of a crash before) and so is Plenum is not 100% success. So why not make the choice yourself.

Everything is good but not everything is good for you. Good day.

[Achilles Tang]

A DSB and Plenum both ultimately achieves what it is made to do.

A DSB is straightforward to setup.

A Plenum takes a lot more effort to setup and is prone to physical collapse if you set it up poorly.

[panlee]

There are a number of systems each can be successful. Read the pro and cons and decide which is best for you. There is no one single best way.

There is one more option for you to think about, which is what I have decided: Go with bare-bottom or almost (use little sand for decorative), built a DSB remotely at a refugium. Go to reefcentral and search "bare" "bottom" and you see alot of discussion on this. If things not work out for me, its not too late also to add sand later. Talking about it...you will find me lelong my #0 sands in marketplace very soon Bought them intended for DSB but not now.

[SpiderOne]

u are forgetting that DSB's LOOK GOOD In the main tank. Give it a Nice natural sea Feel. i would never consider having a tank without a dsb

Note: Above Expression is of my own opinion. I will not be held liable for any flaming that ensues

[Achilles Tang]

Panlee... this new trend of a remote DSB being easily disconnected from the main system is started by alarmists who are worried about the potential heavy metal poisoning accumulating in DSB.

For that matter... anything with a calcium carbonate body can also potentially accumulate heavy metals... so it is suggested to throw out the LRs too.

Anyway for a DSB to be actually effective.. it should occupy the same horizontal surface as the main tank.... so unless you have a sump tank the same size as your main tank... it won't do its job.

Still.... a tiny DSB is probably better than no DSB.

[Nickel]

Bro, I was reading about Plenum last night. Let me know your email I sent the brief article to you. Got it from this forum but dun know which thread now.

It said that for a Plenum to work properly, you need a lot of surface contact with the water at top of the Plenum. I realise this is contradict where LR is used a a filtration mechanism. Hence with sand surface covered by many LR will render Plenum less effective. Further, Plenum needs sand size about 1mm grain, which DSB works better with smaller grain sand (C0?).

What Plenum is trying to creat is a differential vaccum within the sand layer whereby it is sandwiched between a layer almost oxygenless water underneath and the oxgenated normal tank SW above. Whereas DSB create a progreesively oxygenless layer the deeper you go into the sand bed for the 2 types of bacteria to occur.

Believe it is still divided as to Plenum or DSB is better as both has pros and cons, but one needs to be careful to ensure the Plenum is well constructed, else if the support collapse or fresh Sw gets into the Plenum by way of sand-digging LS, it will clash.

Not sure if it make sense to you. But above is from the article. I also thinking whether Plenum or DSB last night. May try out DSB in main tank, Plenum in sump/refugium. Otherwise going for both DSB. Less hassle.

[SpiderOne]

i think thats where eggcrate comes in. to prevent the LR from choking the sandbed . with a DSB in your main tank. why do u still need another one in the sump

[Anthony]

i go for DSB in main tank and plenum in refugium

[Nickel]

Anthony, great minds think alike.

On my drawing board now is a main tank with DSB. Will do a Plenum for the sump/refugium that is displayed and will house slow moving LS such as Seahorse (non sand-digging too ).

Will be talking to tank makers this two week to put plans into reality. Any ideas or lobang for quality(+low cost) tank makers, pls PM me.

[Black]

Ha Ha..Juz reminded me of what I was. The more I read...the more opinion I got....the more confused n undecisive I was. Juz have to make my own decision n go for it. good luck.

[Achilles Tang]

If you have the time & budget, do a plenum sandbed.

Straightforward folks, just dump sand in and voila... a DSB!

[panlee]

Panlee... this new trend of a remote DSB being easily disconnected from the main system is started by alarmists who are worried about the potential heavy metal poisoning accumulating in DSB.

Why no DSB in main tank for me:

1. I have a small 2 ft tank, when I stir the sand bed I can see lots of detritus. I don't feel comfortable seeing so much rubbish at bottom of my tank. I also like to heavy feed. I know I should have introduce more cleanup crews. But I am concern if the clean up crew can manage to reduce the builtup. It is said that in such closed systems, you need lots of lots of cleanuup crew to maintain the balance. And its difficult to measure and thus I would not know how much is enough.

2. There is no way to export the metal build up in DSB. Even Dr Ron, the famous expert in DSB advice people to redo DSB every 4-5 years. His tank crash also. I know DSB can work well but I do not like the idea of having to redo my tank.

3. DSB is not the cure all system. It is current trend. It is like this: Underwater Gravel Filter->WetDry Filter->Plenums->DSB. DSB also I believe being pushed aggressively by commercial outfit because for DSB you need to buy cleanup critters. There is one US commercial page (sorry can not find it) who sells critters packages and in this web page there are alot of link to why you need a DSB. There is such a market and the popularity of DSB is partly due to this economy push.

4. I am not sure if the trend is started by alarmists or not. But I know that there are experts advocating no DSB in main tank. And director of a public aquarium in San Francisco also. I mean can not so many people follow blindly one.

I am not saying DSB does not work. I just choose not to use it in my main tank.

[Anthony]

plenum system...

u can buy those super fine netting (white in colour, u can even see the holes ) at kelantan lane... i m using it for my #1 #0 for my plenum.

remember to fill ur tank with water then install ur plenum.

for cheap sump tank... go for w**yang (got commission or nt )

[clowntrigger]

plenum system...

u can buy those super fine netting (white in colour, u can even see the holes ) at kelantan lane... i m using it for my #1 #0 for my plenum.

remember to fill ur tank with water then install ur plenum.

for cheap sump tank... go for w**yang (got commission or nt )

Just a word of caution if you are getting netting for plenum. I know someone who bought netting for use in Aquarium from some other source and in the end, the netting starts to melt and stick onto the LR stacker. Those netting are those black in colour ones, so just be careful when getting netting for aquarium use.... just my input..

[Achilles Tang]

Well... I am a convinced DSB advocate coz I never could get rid of my nitrates in my newbie phase until I made one.

Actually, Dr Ron has been a rather weird fella at times coz he even said that skimmers are useless before! He is now telling people that tank crashes happen coz of heavy metal buildups. So that means that sandbed and LR has to also change out every 4 to 5 years?? It happened to him and a few reefers but there are a lot of DSB users who have their reef tanks still doing good after 15 years!

Perhaps that's why there are further studies on saltmixes now, to find one that contains less heavy metals in them. That should be the root of the problem and let's not throw the baby out with the bathwater!

To me, throwing out LRs will be much more expensive than a sandbed.

[panlee]

The thing about redoing tank....you wait for many weeks/months for tank to be stable and you have to wait again...huh... With a remote DSB, I can throw it away, unplug it and replace without affecting the main tank. I am convinced DSB works but until I feel comfortable with it in my main tank... Anyway its not too late if I decide to add DSB later.

[WLSS]

Thanks to all that responded.

Have not heard from those who currently use plenum in their main tank ...

Both ways work.

DSB is easy to set up, but there is this risk of hydrogen sulfide's presence. If any crashes happen, the idea of re-doing your tank is daunting... But then, no way is 100% safe.

Plenum is harder to set up. No LR is required, and this does not put some (or just myself) at ease, cos we know the "wonders" of LR. But, it is said that this system will be freed from hydrogen sulfide threats.

panlee, I may PM you to ask about the #0 sand, should I decide to go for DSB.

Anthony, I may PM you to ask about the net, should I decide to go for plenum.

Many thanks to you guys!

[Achilles Tang]

The dangers of Hydrogen Sulfide is overated as no one should be disturbing a DSB in the first place. The smell of hydrogen sulfide is stronger than its toxicity!

Even a plenum system will develop hydrogen sulfide if a tank is allowed to stagnate with no water circulation and no oxygen is diffused to the aerobic/anoxic sections of the sandbed.

[Achilles Tang]

I dug this out from my archives...

Interesting read! Click here!

[Anthony]

Just a word of caution if you are getting netting for plenum. I know someone who bought netting for use in Aquarium from some other source and in the end, the netting starts to melt and stick onto the LR stacker. Those netting are those black in colour ones, so just be careful when getting netting for aquarium use.... just my input..

ohh i m using white netting ... those type u used it to filter ur flour.

[IanJ]

I think they both work, DSB is easier to set-up.

Go with what you are comfortable with.

I am just in the process of removing my DSB as i feel after 8 months its not going the way i had planned. Basically i can say in my case that the life that is essential for DSB's to function had yet to happen.

[terryansimon]

Well... I am a convinced DSB advocate coz I never could get rid of my nitrates in my newbie phase until I made one.

Actually, Dr Ron has been a rather weird fella at times coz he even said that skimmers are useless before! He is now telling people that tank crashes happen coz of heavy metal buildups. So that means that sandbed and LR has to also change out every 4 to 5 years?? It happened to him and a few reefers but there are a lot of DSB users who have their reef tanks still doing good after 15 years!

Perhaps that's why there are further studies on saltmixes now, to find one that contains less heavy metals in them. That should be the root of the problem and let's not throw the baby out with the bathwater!

To me, throwing out LRs will be much more expensive than a sandbed.

so your DSB is part of your main tank or sump setup? coz like what I posted in one of the threads, it was strongly advised against by jon of cor@lf@rm. I'm confused now.

or can I just dump the sand in my sump instead and have a thin layer for my main tank? what are the pros and cons of those? would appreciate it if the advise came from you. you sound like a pro to me. pro as in professional. lets not think wayward here.

[MalaysiaBoleh]

Why no DSB in main tank for me:

1. I have a small 2 ft tank, when I stir the sand bed I can see lots of detritus. I don't feel comfortable seeing so much rubbish at bottom of my tank. I also like to heavy feed. I know I should have introduce more cleanup crews. But I am concern if the clean up crew can manage to reduce the builtup. It is said that in such closed systems, you need lots of lots of cleanuup crew to maintain the balance. And its difficult to measure and thus I would not know how much is enough.

2. There is no way to export the metal build up in DSB. Even Dr Ron, the famous expert in DSB advice people to redo DSB every 4-5 years. His tank crash also. I know DSB can work well but I do not like the idea of having to redo my tank.

3. DSB is not the cure all system. It is current trend. It is like this: Underwater Gravel Filter->WetDry Filter->Plenums->DSB. DSB also I believe being pushed aggressively by commercial outfit because for DSB you need to buy cleanup critters. There is one US commercial page (sorry can not find it) who sells critters packages and in this web page there are alot of link to why you need a DSB. There is such a market and the popularity of DSB is partly due to this economy push.

4. I am not sure if the trend is started by alarmists or not. But I know that there are experts advocating no DSB in main tank. And director of a public aquarium in San Francisco also. I mean can not so many people follow blindly one.

I am not saying DSB does not work. I just choose not to use it in my main tank.

i also read about Dr Ron's tank crash at reefcentral and I am wondering as to how a guy who claimed to have more than 30 years experience in marine science took more than 30 years to conclude that DSB crashes. Since many claim that DSB has an average life cycle of 2-3 years, then how come it took so long for him to realise? After all, as a strong advocator of DSB all this while until now, shouldn't he know about it tens of years ago?

[BarraCudaTM]

I'm building a new 4x2.5x2.5 tank and I wont be using DSB nor plenum.

Reasons that I wont be using DSB includes

1) The weight of the sand

2) The tedious washing of the sand

3) Its a Phosphate magnet

4) Possible heavy metal contamination

5) Possible crash as diversity of critters would not remain balanced after a few years due to competition.

Most likely I would be laying 2" sand just for the look and going for a full time 3ft refugium