Plenum Questions
- Thread starter benihuma
- Start date
q
Member
If you do a couple of searches it will yeald some good info.
Now to the question, A plenium is a water void under the sand bed. It is created by placing eggcrate (used with florescent lighing) and a screen over it to keep sand from filling the space. It covers the tank bottom less an inch or so around the edges. The sand it 4 inches thick and the space 1 inch.
The grain size of the sand is recommended to be 1-4 MM ranging more toward the bigger particles. The reason for this is better water movement.
The water movement comes form the differences in the ORP (Oxygen Redox Potential) levels. Sory I don't know my chemistry to properly explain it but is is basically measuring oxygen. (Don't flame me for the answer I know it isn't right just type in the correct answer if you care.) Tank water has a + number and the Oxygen depleted sand bed has a - number. So the water moves from + to -. The purpose of the plenium is that the plenium still has a - value but less then the sand above it thus not making a "nutrient sink". A "nutrient sink" is when it only captures waste and builds it up which will eventually release back into the tank.
The people for it say it is suposed to be a more efficient form of nitrate reduction as compared to a DSB. This is where the debate starts and where I will leave it.
How does a DSB differ you may ask? A DSB is 4 inches thick but has a smaller grain size. Depending on who you ask it should be .2-1 MM. A DSB also has life in it keeping it clean. A plenium will also have some life but a DSB place an emphasis on it as benificial and a plenium says it can be harmful.
The differences in the process of a plenium and DSB are as such. The people for a plenium believe that there are 3 levels of bacteria. High O2, Reduces O2, and finally no O2. A plenium will allow for reduced O2 areas and DSB will not. The debate is wheather the O2 is good or not. More to the debte but my fingers are getting tired so do the search
.
I was giong to use a plenium but decided not to because of the ratio of DSB to Plenium tanks. More DSB tanks and they are really sucessful. Both systems reduce nitrates and both systems seam to work. There are some scientific questions that were raise about the plenium that have not been answered well enough for me. So until they are it is a DSB for me.
I really hope this answered you question. If not ask me to clarify.
Now to the question, A plenium is a water void under the sand bed. It is created by placing eggcrate (used with florescent lighing) and a screen over it to keep sand from filling the space. It covers the tank bottom less an inch or so around the edges. The sand it 4 inches thick and the space 1 inch.
The grain size of the sand is recommended to be 1-4 MM ranging more toward the bigger particles. The reason for this is better water movement.
The water movement comes form the differences in the ORP (Oxygen Redox Potential) levels. Sory I don't know my chemistry to properly explain it but is is basically measuring oxygen. (Don't flame me for the answer I know it isn't right just type in the correct answer if you care.) Tank water has a + number and the Oxygen depleted sand bed has a - number. So the water moves from + to -. The purpose of the plenium is that the plenium still has a - value but less then the sand above it thus not making a "nutrient sink". A "nutrient sink" is when it only captures waste and builds it up which will eventually release back into the tank.
The people for it say it is suposed to be a more efficient form of nitrate reduction as compared to a DSB. This is where the debate starts and where I will leave it.
How does a DSB differ you may ask? A DSB is 4 inches thick but has a smaller grain size. Depending on who you ask it should be .2-1 MM. A DSB also has life in it keeping it clean. A plenium will also have some life but a DSB place an emphasis on it as benificial and a plenium says it can be harmful.
The differences in the process of a plenium and DSB are as such. The people for a plenium believe that there are 3 levels of bacteria. High O2, Reduces O2, and finally no O2. A plenium will allow for reduced O2 areas and DSB will not. The debate is wheather the O2 is good or not. More to the debte but my fingers are getting tired so do the search
.I was giong to use a plenium but decided not to because of the ratio of DSB to Plenium tanks. More DSB tanks and they are really sucessful. Both systems reduce nitrates and both systems seam to work. There are some scientific questions that were raise about the plenium that have not been answered well enough for me. So until they are it is a DSB for me.
I really hope this answered you question. If not ask me to clarify.
h2o
Member
The plenum is designed to have water under it at all times:
1" pvc pipe joints(to support the plastic grid) HD)
plenum grid(light diffuser or eggcrate from HD)
fiberglass window screen( 1 layer) - i wrapped it around eggcrate and joints using small plastic straps from HD
3+" of Seaflor special grade reef aragonite sand
1 bag of Natures Ocean LS
1" pvc pipe joints(to support the plastic grid) HD)
plenum grid(light diffuser or eggcrate from HD)
fiberglass window screen( 1 layer) - i wrapped it around eggcrate and joints using small plastic straps from HD
3+" of Seaflor special grade reef aragonite sand
1 bag of Natures Ocean LS
kung fu
Member
Hi there...I'm an real newbie to reef systems so please bear with the silly questions!
I'm currently working with my local reef store and am setting up my first reef tank. With their suggestion we are going with a plenum set up. What is a DSB? (Is this the other style of 'natural filter system' that I've also considered with a below tank sump in a small aquarium also utilizing photosynth and aerobic bacteria and such?)
Also, I would think that combining both types of systems would be very beneficial!
Peace...
I'm currently working with my local reef store and am setting up my first reef tank. With their suggestion we are going with a plenum set up. What is a DSB? (Is this the other style of 'natural filter system' that I've also considered with a below tank sump in a small aquarium also utilizing photosynth and aerobic bacteria and such?)
Also, I would think that combining both types of systems would be very beneficial!
Peace...
wally
Member
Hi Kung Fu,
Welcome to the board.
To answer your question a DSB or Deep Sand Bed is a layer deep layer of sand. The deeper the better. For best results most people agree that you need at least a 4" layer of sand. The idea behind this is that at the deeper parts of the bed there is very low oxygen levels in the water. At low oxygen levels a special kind of bacteria grows that converts the nitrates in the water into nitrogen gas, which then just bubbles up and out of the water. In order for this to work you also need critters in the sand like worms and pods to keep the sand stirred.
A plenum does the same thing only it does it by having a layer of water under the sand which becomes low in oxygen and you do not need the sand critters.
There is a HUGE debate right now over which system is better than the other. If done right both systems work out quite well, if done bad both can be a disaster.
There is another method that I have been hearing about as well that is kind of a hybrid between the two. In this method you use something called cell-pore which comes in 9x9x1 inch sheets on the very bottom of your tank and put the sand over it. It gives you a very effective plenum area that is even better since it has a ton of area for the bacteria to grow on. But because its a very pourus material its also like a sand bed. I know several people who SWEAR by it.
Welcome to the board.
To answer your question a DSB or Deep Sand Bed is a layer deep layer of sand. The deeper the better. For best results most people agree that you need at least a 4" layer of sand. The idea behind this is that at the deeper parts of the bed there is very low oxygen levels in the water. At low oxygen levels a special kind of bacteria grows that converts the nitrates in the water into nitrogen gas, which then just bubbles up and out of the water. In order for this to work you also need critters in the sand like worms and pods to keep the sand stirred.
A plenum does the same thing only it does it by having a layer of water under the sand which becomes low in oxygen and you do not need the sand critters.
There is a HUGE debate right now over which system is better than the other. If done right both systems work out quite well, if done bad both can be a disaster.
There is another method that I have been hearing about as well that is kind of a hybrid between the two. In this method you use something called cell-pore which comes in 9x9x1 inch sheets on the very bottom of your tank and put the sand over it. It gives you a very effective plenum area that is even better since it has a ton of area for the bacteria to grow on. But because its a very pourus material its also like a sand bed. I know several people who SWEAR by it.
kung fu
Member
Thanks for the welcome! (I've been planning on getting into reef tanks for a good year now so I'm really excited to get my tank this week!)
So...from reading up on all this...by utilizing a plenum AND a deep sand bed (as well as possibly adding a photosynthesis undertank sump system down the road) we're basically combining different effective systems to get the best possible result.(?)
(I'll also be utilizing a protein skimmer as well).
I have to admit I was REALLY impressed with the 'natural' filter systems that I've looked at. Until my local shop brought the idea to me I had been planning on 'old style' bio-wheel filters w/ the protein skimmer (and filtered mains water). But the 'natural' ways are incredible!!
Peace...
So...from reading up on all this...by utilizing a plenum AND a deep sand bed (as well as possibly adding a photosynthesis undertank sump system down the road) we're basically combining different effective systems to get the best possible result.(?)
(I'll also be utilizing a protein skimmer as well).
I have to admit I was REALLY impressed with the 'natural' filter systems that I've looked at. Until my local shop brought the idea to me I had been planning on 'old style' bio-wheel filters w/ the protein skimmer (and filtered mains water). But the 'natural' ways are incredible!!
Peace...