Plenum or Insanity?

[florida joe]

Originally Posted by candycane
http:///forum/post/2577783
It makes me wonder about forced motion under the plenum, just enough to keep water movement going to force oxygen up and not down maybe, who knows. Something like those long plastic magnetic strips on all four sides of the plenum so that they are placed in a certain way where they are all pushing against eachother. I would think this would get the water to move and create a more favorable enviroment. Something like 12 GPH,

. Who knows..........may work or may not.
Candy I think I would be better served if the water under my plenum was still this remaining in a near zero oxygen level feeding the denitrification bacterial on the mud and screen above it

 

[florida joe]

Boys and girls let me run this one up the flag pole and see if anyone salutes it. (I always wanted to say that). My original plan was to go with a straight mud refug, enter Randy and that changed to a split refug with mud and a plenum on one side and sand over CC on the other. I was going and may still equally divide the refug with a piece of acrylic or glass, which will be easier to get. BUT what if I go with roughly 8 ½ inches of sand and use rubble rock seeded with a broken up piece of LR from my DT. Then 17inches of mud over plenum followed by another divider of rock and then the remaining area sand. Thus give me the added advantage of live rock in my refug. I was thinking going with 4inches of sand two of mud and may as much as six inches of sand at the opposite end. Thus giving me not only a mixed media bed but a varied depth bed as well.

 

[scopus tang]

Originally Posted by candycane
http:///forum/post/2577783
It makes me wonder about forced motion under the plenum, just enough to keep water movement going to force oxygen up and not down maybe, who knows. Something like those long plastic magnetic strips on all four sides of the plenum so that they are placed in a certain way where they are all pushing against eachother. I would think this would get the water to move and create a more favorable enviroment. Something like 12 GPH,

. Who knows..........may work or may not.
Water movement is one of those interesting issues when you start looking at plenums. Obviously there has to be some water movement, but how much is too much or too little

. I know that in at least one case that I am aware of, the site recommends using a standpipe with a powerhead to circulate water initially for about a month, then the powerhead is removed and the standpipe is capped. After that the system relies only on the trickling movement of water through the sand bed. My concern here would obviously be that if you moved the water too quickly, you would end up moving oxygenated water below the plenum, thus reducing the overal effectiveness of the system (i.e. decreasing the aneorobic mid layer).

 

[scopus tang]

Originally Posted by florida joe
http:///forum/post/2577942
Boys and girls let me run this one up the flag pole and see if anyone salutes it. (I always wanted to say that). My original plan was to go with a straight mud refug, enter Randy and that changed to a split refug with mud and a plenum on one side and sand over CC on the other. I was going and may still equally divide the refug with a piece of acrylic or glass, which will be easier to get. BUT what if I go with roughly 8 ½ inches of sand and use rubble rock seeded with a broken up piece of LR from my DT. Then 17inches of mud over plenum followed by another divider of rock and then the remaining area sand. Thus give me the added advantage of live rock in my refug. I was thinking going with 4inches of sand two of mud and may as much as six inches of sand at the opposite end. Thus giving me not only a mixed media bed but a varied depth bed as well.
Joe, any chance you can give use a diagram? I think I'm following you here, but I'm not really sure.

 

[florida joe]

Originally Posted by Scopus Tang
http:///forum/post/2578053
Water movement is one of those interesting issues when you start looking at plenums. Obviously there has to be some water movement, but how much is too much or too little

. I know that in at least one case that I am aware of, the site recommends using a standpipe with a powerhead to circulate water initially for about a month, then the powerhead is removed and the standpipe is capped. After that the system relies only on the trickling movement of water through the sand bed. My concern here would obviously be that if you moved the water too quickly, you would end up moving oxygenated water below the plenum, thus reducing the overal effectiveness of the system (i.e. decreasing the aneorobic mid layer).
exactly my conseron, to much oxygen

 

[florida joe]

Originally Posted by Scopus Tang
http:///forum/post/2578055
Joe, any chance you can give use a diagram? I think I'm following you here, but I'm not really sure.
will start on on now,
Tank passed the leak test water Is pumped out I will now take the doors and hinges off and try to get the box in then take it out and play around with what I am going to do with the divider and plumbing (install the bulk head est.) a smart person would have made a mock out of cardboard and tried the fit but I think my measurements are ok we shall see.
I think I will go with you PVC vertical influent pipe BUT as this water is coming from my DT skimmer boxes and before my mechanical blue/white filter material I am thinking of going with a ¾ to ½ inch adapter and a coupling so I can stuff the ¾ with filter material and remove it each week when I do water changes and clean the material of build up. It just goes on and on

 

[scopus tang]

Originally Posted by florida joe
http:///forum/post/2578071
will start on on now,
Tank passed the leak test water Is pumped out I will now take the doors and hinges off and try to get the box in then take it out and play around with what I am going to do with the divider and plumbing (install the bulk head est.) a smart person would have made a mock out of cardboard and tried the fit but I think my measurements are ok we shall see.
I think I will go with you PVC vertical influent pipe BUT as this water is coming from my DT skimmer boxes and before my mechanical blue/white filter material I am thinking of going with a ¾ to ½ inch adapter and a coupling so I can stuff the ¾ with filter material and remove it each week when I do water changes and clean the material of build up. It just goes on and on

Yeah, but isn't it fun?! This is almost as good as getting to set-up a new system myself ~ almost. Hurry! hurry! Want to see more pictures.
Think you'll have to change the blue/white filter material at least once a week if not more, thats how often I have to change it in the bottom of my skimmer bubble diffuser box.

 

[florida joe]

Originally Posted by Scopus Tang
http:///forum/post/2578130
Yeah, but isn't it fun?! This is almost as good as getting to set-up a new system myself ~ almost. Hurry! hurry! Want to see more pictures.
Think you'll have to change the blue/white filter material at least once a week if not more, thats how often I have to change it in the bottom of my skimmer bubble diffuser box.
yes I will change the filter material every week when I do water changes
Randy I send you an e-mail I will post some pics as I try to get the box in, I will have to remove the doors and hinges to do so and keep them off until the project is complete that should go over big with my wife, I do get so tired of sleeping with one eye open.

 

[florida joe]

Ok boys and girls this is what we are working with.

Opening is 24”X21” and 8 ¾” from the inside face to the front of my sump

 

[scopus tang]

Originally Posted by florida joe
http:///forum/post/2577942
Boys and girls let me run this one up the flag pole and see if anyone salutes it. (I always wanted to say that). My original plan was to go with a straight mud refug, enter Randy and that changed to a split refug with mud and a plenum on one side and sand over CC on the other. I was going and may still equally divide the refug with a piece of acrylic or glass, which will be easier to get. BUT what if I go with roughly 8 ½ inches of sand and use rubble rock seeded with a broken up piece of LR from my DT. Then 17inches of mud over plenum followed by another divider of rock and then the remaining area sand. Thus give me the added advantage of live rock in my refug. I was thinking going with 4inches of sand two of mud and may as much as six inches of sand at the opposite end. Thus giving me not only a mixed media bed but a varied depth bed as well.
Ok, for those who couldn't visualize what Joe was suggesting, here's a diagram.

Joe, I know that Dennis210 does something similar to what you are proposing in his DT. However unless I'm mistaken he has a plenum on each end (covered only by a DSB), and a DSB only in the middle. Perhaps he'll pop in and give us some input on this (I'll PM him and tell him to check the updates).

 

[florida joe]

IT FITS, IT FITS

I will now remove it and start the plumbing I had to move the centerline of the refug off the centerline of the sump so the effluent would dump straight into the sump more miscalculating on my part. I will go with a tee, and a valve to gravity feed from the white PVC you see over the sump and the will tie it into my influent with barb fittings and hose. With the refug in place I can still do maintenance on my sump and protein skimmer

 

[scopus tang]

Ah! In front of the sump. I was envisioning you try to manipulate that sucker in behind your sump. Given were it is going to sit, harvesting algae shouldn't be such a big deal, although you will still have the mud clinging to rhizomes issue.

 

[florida joe]

Yea pal I have been giving that some thought when I harvest I will cut down to the mud in some places to poke around and see how impacted it is when it gets to bad I will remove the mud best I can dry it out remove as much of the rhizomes as I can and put it back with some added minerals if that is to much of a headache I will just replace the mud. I don’t think I will have an issue for a while though
Any thoughts on my LR divider idea ?

 

[scopus tang]

Originally Posted by florida joe
http:///forum/post/2578446
Yea pal I have been giving that some thought when I harvest I will cut down to the mud in some places to poke around and see how impacted it is when it gets to bad I will remove the mud best I can dry it out remove as much of the rhizomes as I can and put it back with some added minerals if that is to much of a headache I will just replace the mud. I don’t think I will have an issue for a while though
Any thoughts on my LR divider idea ?
Sounds reasonable to me. I've been kicking the 3 way split around in my head, being an experimental kind of guy, I like the idea. I do see some issues however.
#1; how are you going to seal the rock dividers so that no water (and therefore oxygen) is able to move between the layers? Might be better served by going with plexi dividers (tried siliconing rock tight when I built my bog tank, and its a lot harder to do than it sounds ~ never did get the rock water tight)
#2; assume that your going to place screen dividers between sections or are you going to allow macro to spread to all areas?
#3; be sure to include a screen between the CC and sand, otherwise the sand will filter down defeating the "plenum" idea.
#4; still not sure of overall depth of section 3, I would go deeper.
Also on section 1 are you placing CC, sand, and rubble on top of the sand, or just sand over CC? At a 2" depth it shouldn't be anaerobic, not sure what you are looking for on this section?

 

[sepulatian]

Nice project Joe! I have not really read up too much on plenums. This is very informative

 

[florida joe]

Originally Posted by sepulatian
http:///forum/post/2578904
Nice project Joe! I have not really read up too much on plenums. This is very informative

Thanks Sir Q you taking the time to read this on going project means a lot to me

 

[florida joe]

Originally Posted by Scopus Tang
http:///forum/post/2578486
Sounds reasonable to me. I've been kicking the 3 way split around in my head, being an experimental kind of guy, I like the idea. I do see some issues however.
#1; how are you going to seal the rock dividers so that no water (and therefore oxygen) is able to move between the layers? Might be better served by going with plexi dividers (tried siliconing rock tight when I built my bog tank, and its a lot harder to do than it sounds ~ never did get the rock water tight)
#2; assume that your going to place screen dividers between sections or are you going to allow macro to spread to all areas?
#3; be sure to include a screen between the CC and sand, otherwise the sand will filter down defeating the "plenum" idea.
#4; still not sure of overall depth of section 3, I would go deeper.
Also on section 1 are you placing CC, sand, and rubble on top of the sand, or just sand over CC? At a 2" depth it shouldn't be anaerobic, not sure what you are looking for on this section?
Randy I must admit I was not sure what your concern was over the rock allowing water to transfer from one section to another. Then after reading your post a few times and a glass of good Port after dinner I think I understand what you are saying.
With the varying heights of the substraight a horizontal flow of water would in fact have a shear effect on the substraight not passing over it but potentially passing through the side and doing so delivering oxygen rich water to the multi levels of the substraight in effect negating the areas of anaerobic bacteria we are trying to cultivate.
My good friends am I some where in the same ball park as you are?
I will address your other comments tomorrow

 

[scopus tang]

Originally Posted by florida joe
http:///forum/post/2579352
Randy I must admit I was not sure what your concern was over the rock allowing water to transfer from one section to another. Then after reading your post a few times and a glass of good Port after dinner I think I understand what you are saying.
With the varying heights of the substraight a horizontal flow of water would in fact have a shear effect on the substraight not passing over it but potentially passing through the side and doing so delivering oxygen rich water to the multi levels of the substraight in effect negating the areas of anaerobic bacteria we are trying to cultivate.
My good friends am I some where in the same ball park as you are?
I will address your other comments tomorrow
Yep you got it, sorry for the confusion. Any progress on the plumbing?

 

[florida joe]

Originally Posted by Scopus Tang
http:///forum/post/2579361
Yep you got it, sorry for the confusion. Any progress on the plumbing?
Well to day I hope to tie into the gravity feed with a tee and valve both the feed to my sump and refug and reduce the ¾ to ½. I will also take a piece of plate glass to be cut for my divider. With the opening being as such I am going back to one midpoint divide I was thinking 6” high. I will have the glass cut and see if I can get some plastic angle cut four small pieces and glue them to the glass so it is removable or allow me to move it off center line if at some time I wish to do so
Will discuss the screening when I get back

 

[dennis210]

Okay Joe - is it possible for you to glue in plexiglass dividers for your middle mud chamber. If you make a small plenum - sit it on the bottom - cover it with 1.5 to 2 inches of substrate - place a screen over that area - and then place another 1.5 to 2 inches of mud over that. I would suggest 7 inch dividers.
Reasoning is that the finer particulate mud will filter thru your rock dividers.
Plexi will allow best chance at zero water infiltration from the sides.
As far as discussion of mixing mud over some other substate - a word of cuation - the fine particulate size in mud will allow it to infiltrate down thru any other substrate of a larger particulate size. In so doing it will block off or at least severely limit water movement through that layer. Also when screening off layers in plenum these same finer particulates will pass thru the screen. In theory and on paper at least the only answer I find is to use all mud in and around plenum or go ahead and use a sand substrate in the lower layer that is the finest grain size you can find.
Also when deciding three years ago how to set up my own DT I was torn between plenums and just a DSB. Being rather confused after weeks of reading everything I could I decided on both. The 72 inch footprint has a plenum on either end with a 6 in DSB between them. The substrate is really active with micro stars, nassarius snails, and cerith snails. This has worked well for me.
Randy knows - I hate to input on threads anymore - even when I want to.
Too many times I have been blasted as "not knowing anything". However this thread takes me back to discussions in a student union with friends while
researching. It's a think tank type of thing where all reading can learn something. Once again GREAT THREAD!
Dennis