Plenums and the wasting "option"

["Umm fish?"]

If you keep the DSB external, you don't have to worry about your display crashing, and can change the DSB out easily.

This is true, but a lot of us would like to keep animals that need deep beds. And if you need a deep bed, it just makes sense to try to come up with a strategy that will try to keep the bed healthy for the long term.

We're really planning here for the post-4 to 5 year mark where it's said that some sand beds have trouble. I don't want that to happen to me. So I'm trying to plan for it....

 

[barryhc]

I still think having a drain with a DSB is way more complicated than having a drain with an SSB - and having the DSB external to the display (such as in fuge or even Calfo-style bucket), or even not having a DSB at all if you have sufficient live rock to do all the denitrification.

I am not bashing anyones' attempts to get a drain to work with DSB, just remarking that it gets very complicated trying to maintain the anaerobic layer, and worrying about how much, how often, whether you are hurting the anaerobes, etc. IMO, much easier to keep the DSB external (or not use one), and use the drain on the SSB to keep it from filling with gunk.

Complicated "my foot"!!

"Fish", in as much as you insist on being a "lowly" infrequent flyer . . er . . . waster . . . er, well, whatever, You are obviously a man after my own heart. :lol: :lol:

Thanks, so much. > barryhc :beachbum:

 

["Umm fish?"]

Complicated "my foot"!!

Yeah, I'd say the siphon is a pretty proven technology. At least, MY siphon is pretty proven. Sigh. I'm raising some FW fry and the daily 50% WC is wearing me out.

Thanks for the love. I'm in work hell and really procrastinating at the moment....

 

[barryhc]

Hell, I'm in "work heaven", are you looking for a career change? :lol:

> barryhc :beachbum:

 

["Umm fish?"]

Hell, I'm in "work heaven", are you looking for a career change?

> barryhc

No, this too shall pass. If I'd hire more employees then I could take more time off. But, if I hire more employees, then I'd have to pay them (they are all so unreasonable that way).

Actually, my only employees are myself and my lovely bride. She's sick today, so I'm putting out her fires, too. Sigh....

We're just about to the end of our busy season, though.

 

[barryhc]

I have myself and my son ( just recently with my son ), "wife" handles "paper" mostly at night or on weekends. Had a bunch of "gorrilas" years ago, gave up for a while on gorillas, and just ran by myself. Were "firing up" again now with my son "on board", and were going to start with chimpanzees this time.

Gotta run. good night.

> barryhc :beachbum:

 

[reefclown]

Ok, now a dumb question--if we know phosphates can be processed in a fuge with macro, and we know DSB works well on its own processing nitrogenous wastes, at least for a time, why bother with plenum wasting?

Just for the sport of it

You can easily keep a system stocked with corals and few yards of fish using the proven methods, BB, DBS,e.tc. Now if the challenge was to continually up the fish stocking level to the capabilities of the system then some play is required.

The wasting plenum is just another idea to play with, sadistic maybe, but an idea to play with none the less

Just be kinda interesting to see what kinda mileage/flexibility it could provide in the handling of P and N.

I absolutely ABHORE the idea of drawing oxygenated water through the "Anoxic-zone" ( no oxygen ). In fact, if oxygenated water is drawn through the "no-oxygen" zone, then it isn't "Anoxic" anymore, is it? Sounds like a bad idea.

I'm having a chilled eve, so not going to start thinking:bum:


But for when the neurons kick in, are you planning to control/alter the depth of all 3 sediment zones or just the aerobic and anaerobic.
Why play with 2, when there are 3?

 

[barryhc]

Just for the sport of it

You can easily keep a system stocked with corals and few yards of fish using the proven methods, BB, DBS,e.tc. Now if the challenge was to continually up the fish stocking level to the capabilities of the system then some play is required.

The wasting plenum is just another idea to play with, sadistic maybe, but an idea to play with none the less

Just be kinda interesting to see what kinda mileage/flexibility it could provide in the handling of P and N.

Very good ReefClown, I couldn't have said it better. :thumbsup:

Of course, we don't want to forget the "nasties" that go "down the drain", instead of back up into the water column "eventually-maybe". ( The "forever-sand-bed"! )

But for when the neurons kick in, are you planning to control/alter the depth of all 3 sediment zones or just the aerobic and anaerobic.
Why play with 2, when there are 3?

Start on page 9, especially the post immediately prior to your first post, which discusses the three zones, and how they are "stretched".

Get those neurons "firing" again. > barryhc :beachbum:

 

[salty joe]

This is a good thread. I hope we can keep it going for years and years, because we're going to need to. Speaking of long threads, timewise that is, I wonder what the longest running thread that stayed active is on reef Central.? Thanks for all the interesting reading and links. I can hardly wait to see results from water that was drawn from the plenum. Thanks again.
Joe

 

["Umm fish?"]

Hey barryhc! I wonder if I could ask your advice. I roughed out the manifold. I've just finished setting up my drill press. I'm ready to drill the siphon holes. What size holes do you think I should drill?

The tank is 4' x 2' - 4" or so in depth to make room for the overflows. The manifold is a basic rectangle, with crosses every 4.5" or so. That means I can only fit in a couple of holes per piece of pvc (in between the crosses). Thanks!

Andy

 

[barryhc]

Andy, the size and number of holes has to do with flow balancing. Flow balanicng occurs as a result of several factors, but flow restriction is the primary factor here as regards size and number of holes.

The total area of your drilled holes needs to be significantly less than the area of your "feeder tube" for a given "section" of plenum that your main feeder tube supplies.

"Best flow balancing" is obtained with a ratio between "total feed hole area" and "flow tube area" of .5 to 1, with "adequate " results at .75 to 1, and "poor balancing" as you approach 1 to 1.

I assume that you have "roughed in" with 1/2"PVC. If you have only one supply tube, and with an I.D. of .580" dia., then you have .29 squared x Pi = .264 sq. in. for your single flow tube.

For "adequate balancing" then, you want .75 x .264 = .2 sq. in. "total feed hole area". Since number of holes is dependent on hole size, let's try a 3/64" dia. hole, and solve for number of holes.

To simplify this since we are dealing with a ratio, we can eliminate Pi, and radius from both sides of the equation. So, with a 3/64" hole being .047" dia., and 1/2" PVC having an actual Inside dia. of .580", we get: .58 squared / .047 squared = 152 holes at a 1 to 1 ratio. For "adequate balancing" here, we multiply times .75 = 114 holes.

For "best flow balancing" we would have 152 holes x .5 = 76 holes.

Now, there are other factors here, including the area of substrate "covered" by each hole. With a 2' x 4' "area" to cover, you have 1152 sq. in. to cover with only 114 holes, and that comes to 10 sq. in. of substrate area to cover with each hole, which is about a 3.5" square.

If you could complete you installation with either a 3/4" PVC tube, and 2 collection points, or a 1" PVC tube and 4 collection points, that would be highly preferable. Your number of holes would be 2 times or 4 times as many respectively. The basic plenum can remain 1/2" tube.

I hope this helps > barryhc :beachbum:

 

["Umm fish?"]

Thanks barryhc! I've probably already screwed it up (I had finished up the holes tonight before I saw your post). But, I'm still going to put some of the weed ground cover (not the pesticide one) over the holes to screen out the sand, so that will effectively reduce the area of the holes somewhat and I'm not too far off what you suggested. Hopefully it'll work itself out.

Maybe I could work in 4 1" draw tubes, too (two in the center and two on the outside of the overflows).

Can I combine the 4 1" tubes into one 1 1/2" or 2" drain so that one gate valve can control the whole shebang, you think? Bummer, man.

 

[barryhc]

Andy, here is a chart of drain tubes, with appropriate size and number of holes.


drain tube. . .hole dia. . .adequate balancing. .good balancing
. . .1/2". . . . .3/64". . . . . . . .114 holes. . . . . . . . 76 holes
. .(.580"). . . .1/16". . . . . . . . .64. . . . . . . . . . . . .43
. . . .". . . . . .5/64". . . . . . . . .41. . . . . . . . . . . . .28
. . . .". . . . . .3/32". . . . . . . . .29. . . . . . . . . . . . .19

. . .3/4". . . . .3/64". . . . . . . .222. . . . . . . . . . . .148
. .(.810"). . . .1/16". . . . . . . .126. . . . . . . . . . . . .84
. . . .". . . . . .5/64". . . . . . . . .81. . . . . . . . . . . . .54
. . . .". . . . . .3/32". . . . . . . . .56. . . . . . . . . . . . .37

. . . .1". . . . .3/64". . . . . . . . .367. . . . . . . . . . . .245
. .(1.040"). . .1/16". . . . . . . . .208. . . . . . . . . . . .138
. . . .". . . . . .5/64". . . . . . . . .133. . . . . . . . . . . .89
. . . .". . . . . .3/32". . . . . . . . . .92. . . . . . . . . . . .61

1 1/4" use 1.52 x 1" ( # of holes ) values above

1 1/2" use 2.14 x 1" ( # of holes )values above

2" use 3.77 x 1" ( # of holes )values above

For 7/64" dia. use .33 x ( value for 1/16" dia. holes )

For 1/8" dia. use .25 x ( value for 1/16" dia. holes )

The chart above is for a single final drain tube ( or smallest restriction within the drain tube ), however, it can of course, be used for any single "collection point" in a manifold.

So Andy, you could "pipe in" (4) 1/2" PVC collection tubes into a single 1"manifold, and on to a 1" drain.

Your "weed cover" might restrict flow by 50%, and allow twice as many holes of a given size. :dance:

Of course I would reccomend eggcrate, 1.5 mm screen, 1/2"depth of 2-4mm, then 1/2" depth of .7-1.7mm, and then your sand, but that's just me. :idea: :

Happy reef keeping! > barryhc :beachbum: :thumbsup:

 

["Umm fish?"]

I think I'd better go for 2" then. :eek1:

I did 3/32" holes, and I have 464 of 'em. That's what I get for getting a new drill press. Gotta go drill crazy.

With the weed screen, though, that'll get me just barely above the good balancing mark.

Cool. Thanks for the help!

God, that's going to be a mass of water coming out the end of that pipe, though. I'm glad I'm sending it right through the floor and right to the basement sink. Of course, I'll put a bucket under so I can take some test measurements.

I had the plumber out Friday doing things like connecting up the basement sink and cutting into the sewage line. (Having the plumber cut the sewage line instead of me. Priceless.) Man, I'm getting close. The live rock's coming the first part of December!

Hasta!

 

[barryhc]

I did 3/32" holes, and I have 464 of 'em. That's what I get for getting a new drill press. Gotta go drill crazy.

With the weed screen, though, that'll get me just barely above the good balancing mark.

If we use a 50% restriction to account for the "landscape fabric" wrap, you are close to adequate balancing, however, even then, you can only "cover" 58 of these 3/32" holes per "collection point". You REALLY NEED 8 collection points.

If you could bring these 8 collection points into a single horizontal 1 1/2" dia. collection manifold just above the back of the grid, and then to a single 2" drain, you will remain adequately balanced.

Now is the only chance you're going to get, so cut the "back rail" and replace with a new one that includes 8 vertical 1/2" tees, and up to the 1 1/2" collection manifold. :idea:

If you don't get the 8 collection points, you will not cover much of the "surface area".

Go for it Andy, it's "crunch time"!

Best of luck to you. > barryhc :thumbsup:

 

["Umm fish?"]

If you could bring these 8 collection points into a single horizontal 1 1/2" dia. collection manifold just above the back of the grid, and then to a single 2" drain, you will remain adequately balanced.

Well, that's kind of hard to do. I could maybe get it in right next to the grid and right up against the back overflows. I could also have it run straight across the back of the tank and have the 8 collection points come up and over the top. I can also just silicone up half of my holes. Yeah, that might be the best option, 'cause it'll be a lot easier to get four lines up and over the back.

They need a pouty face smilie.

 

[barryhc]

Andy, maybe you could run "pairs" of 1/2" tees to (4) 3/4" "mini manifolds, and run then (4) 3/4" tubes "up and over". It sounds like the overflows are "getting in your way", where are they?

> barryhc :spin2:

 

[barryhc]

Andy, maybe you could run "pairs" of 1/2" tees to (4) 3/4" "mini manifolds, and run then (4) 3/4" tubes "up and over". It sounds like the overflows are "getting in your way", where are they?

> barryhc :spin2:

ooPS > Do you have any images you can post? :bigeyes:

 

["Umm fish?"]

It's one of those reef-ready All Glass 120s. So, there are two big overflow boxes each centered on its half of the rear wall of the tank. Pretty much a pain in the ***. Better than always having to worry about siphons, though. I figure I can pretty much assume that gravity is going to work.

Nope. No pictures yet. My lovely bride is the photographer in the fam and I can't seem to work up a lot of enthusiasm in her to take a bunch of pics of pvc. I'm looking for the digital camera, but no luck yet. Man, kids'll drive everything else out of your brain....

 

[barryhc]

Let's not start om the "kid thing" today, RC is barely handling the traffic today, and we would "blow it up" for sure! :blown:

Maybe you can use a 2 into 1 manifold at each end, and a 4 into 2, or 4 into 1 ( with 1" manifold ) in the middle.

In any case, it seems that you are following the math well, so I'm sure you will make something good happen!

Your bride is in the early stages of a long education!

Give the kids each a popsicle, and crank up the stereo!

> barryhc :dance: :thumbsup: