Deep Sand Bed layering questions

[Modern-Revolution]

ok. this is my sump for my new system. i'm going to run a 6" DSB. i've read a lot, and i've found conflicting information. but this is the way i think it should be done after filtering through the different literature on DSB's. hoping to get some constructive criticism if there is a flaw, or hopefully support in that it is flawless.

my bottom layer will be a plenum so water can flow freely. this is made by a layer of egg crate on top of small cut squares of egg crates in corners like a table. on top of this will be 2 layers of gutter guard to make the gaps much smaller. a thin layer of crushed coral will be on top of this. followed by reef grade aragonite for 3 inches, and finally 2 or 3 inches of oolite fine sand. what do you guys think?

http://i7.photobucket.com/albums/y283/BillOne/20130303_002410.jpg

http://i7.photobucket.com/albums/y283/BillOne/20130303_002328.jpg

http://i7.photobucket.com/albums/y283/BillOne/20130303_002457.jpg

[Modern-Revolution]

Nobody with DBS knowledge?

[Cuddlefish69]

Fine sand on top may become suspended in water and migrate to other parts of your sump or DT depending on how much flow you have. Also I am not sure how much the plenum will work if you don't have direct flow underneath but I guess it won't hurt. Have you considered using this area as a refugium and setting up a remote dsb?

[ridetheducati]

No need for egg crate or screen. Just dump in 6-8" of sand, done.

[coralreefer]

Nobody with DBS knowledge?

Hate to admit I know more than I care to about DSBs I also remember plenums and they are two very different animals. So first you need to decide which you want then research that.

[cherubfish pair]

How do you plan to set this up in conjunction with your equipment vessel, sump?

[Modern-Revolution]

Hate to admit I know more than I care to about DSBs I also remember plenums and they are two very different animals. So first you need to decide which you want then research that.

everything i've read suggests that the first layer should have free space or lr rubble at least. also i've read that a plenum has not been truly proven to benefit the dsb or not. i figured why not just add it anyway? i want it to be as functional as possibly so i figured the space would allow the greatest amount of anaerobic bacteria. i've also seen mised info on if the super fine sand should be on top of the plenum under the courser sand or on top of the courser sand at the top of the dsb. i'm not worried about the oolite sand getting into the return as the flow ill be very low and the dsb/fuge chamber is 14" deep, 8" of water after the 6" dsb.

How do you plan to set this up in conjunction with your equipment vessel, sump?

it's a 55g sump. i plan on a split drain with a return in the center chamber. skimmer on the left and fuge/dsb on the right.
this feeds into 3 30 gallon tanks.

http://i7.photobucket.com/albums/y283/BillOne/20130303_234545.jpg

http://i7.photobucket.com/albums/y283/BillOne/20130304_002018.jpg

http://i7.photobucket.com/albums/y283/BillOne/20130304_001944.jpg

[cherubfish pair]

Okay now I see the bigger picture as you zoom out!

[tonyf]

Looking at the sump ... right hand side, what is the shelf with the eggcrate on it for ?

Understand firstly why we use a DSB ... it is primarily for nitrate reduction. You don't want things growing in it because that slows the water too much and encourages detritus to enter the sand. You don't want detritus entering the sand bed, that is a big NO-NO.

Some advice on construction, IMHO, ditch the plenum idea, get the finest aggregate that you can ... play sand used to be widely used, and get yourself a plastic container at least 6" deep and that will roughly cover the bottom of the 'DSB' compartment. Fill the container with the fine sand and lay it on the bottom of the 'DSB' compartment.

Set the inflow to run across the sand at a velocity just not enough to raise the sand into suspension. Too slow and detritus can enter the sand bed, too fast and the sand bed is blown away.

The plastic container is to allow you to remove the sand bed, without causing any other damage to water quality or having the dirt flow into your display, for maintenance.

Some old Calfo magic http://www.wetwebmedia.com/deepsandbeds.htm & http://forum.marinedepot.com/Topic59558-13-1.aspx

[Modern-Revolution]

ok. i can ditch the plenum. but i still plan on using crushed coral on bottom. araganite reef grade sand in middle. and fine oolite sand for top. i read you get the best bacteria growth that way. i have a ball valve to restrict and add flow to the dsb chamber. why would i ever want to remove the dsb? once it cycles it should remain good i would assume. i have heard of people changing out dsb once a year or whatever but i imagine i would be starting a new cycle if i did that and it doesn't seem necessary as far as i can understand thus far anyway. so why would i remove it?
the egg crate shelf is for live rock. surface area is what's important for a dsb so it's advised to have any rocks suspended.

EDIT: thanks for those links! i'll be reading them shortly.

[ridetheducati]

ok. i can ditch the plenum. but i still plan on using crushed coral on bottom. araganite reef grade sand in middle. and fine oolite sand for top. i read you get the best bacteria growth that way. i have a ball valve to restrict and add flow to the dsb chamber. why would i ever want to remove the dsb? once it cycles it should remain good i would assume. i have heard of people changing out dsb once a year or whatever but i imagine i would be starting a new cycle if i did that and it doesn't seem necessary as far as i can understand thus far anyway. so why would i remove it?
the egg crate shelf is for live rock. surface area is what's important for a dsb so it's advised to have any rocks suspended.

EDIT: thanks for those links! i'll be reading them shortly.


Not sure where you are getting your information, but the crush coral (the largest particle) will be on the top and the smallest particle will be on the bottom. Please continue to research DSB, there is more information you need to grasp. DSB work but not infinitely.

As I said in a previous post, use the finest sand you can find at 6-8" deep and add a couple of detrivore kits, done. Serviceable for 3-5 years.

[forextrader]

Completely agree with previous statement. Don't over think it. Add the finest sand you can find. It packs tighter creating a large anaerobic space for nitrate to be converted to nitrogen. As long as there is not direct water flow aimed at the sand you will not create a whirlwind of sand. Add as much life as you can to the sand bed and you will have no problems.

[Cuddlefish69]

From my understanding, sand does not "cycle" because it is in-organic and can be added to a system at anytime with no ill affect. Over time, sand will become more of a hinderance than a help to your system and can release nitrates. This is why you remove the old and put back new.

[Modern-Revolution]

Read those articles. Thanks for all the advice. Ditching the plenum. Adding 120 lbs. Of oolite sand and no course sands.

[Modern-Revolution]

Also adding a cup of sand from my reef tank and a lb or 2 of garf grunge

[worm5406]

+1 on the sand... I know a few people that like the garf stuff. I have not experience with it.

When I moved to my new 180 I took about 30-50lb of sand and seeded the fiji pink and oolite with it. so 150+ lb sand. I have a 4-5" in the 180 with prob 2" in the fuge of oolite.

Personally I have had ZERO particles fly around. Granted I ran the tank at 100% with two mp40's for the entire cycle so it had a chance to find where it wanted to go.