DSB in a bucket for nitrate control - Page 39

Galtamar · #**951** 06/26/2006, 11:44 AM

Quote:

Originally posted by Avi
Thanks...I had been under the impression that it was necessary to have an area where oxygen in the water wouldn't reach the depth of the sand, thereby fostering a growth of anaerobic bacteria that would consume nitrates because oxygen didn't reach there. If it's surface area that's critical, then you'd be saying that the DSB in a bucket's designed to provide area for aerobic bacteria?

This was already discussed somewhere int his thread. The thing is that after 2 feet of dept the quantity of NO3 consumed is not much. Oxygen will be consumed rapidly at the first 1/3 or so of the bucket after that, the bacteria that predominates are either facultative or anaerobic. No im not saying that surface area in the DSB in a bucket's designed to provide area for aerobic bacteria. You want more area so more gasses can diffuse through the sand. So if u ask what's better depth or superficial area ill tell u that as long as u have at least 18" of depth, go for as much superficial area as u can.

Spuds725 · #**952** 06/28/2006, 11:46 AM

If you have space limitations-- you might want to consider a denitrator (flow through)-- these use extremely slow flow through and denitrate by the same concept (the slow flow allows the limited oxyen to be consumed but nitrifying bacteria at one end and then the rest becomes anerobic to allow the denitrifying bacteria to grow)-- I don't know if sand would be an adequate media especially 4 feet of it to allow flow through-- but something using the 4 feet of PVC could probably be built and hidden behind the tank--

of course a denitrator is a subject for another thread...

Avi · #**953** 06/28/2006, 01:33 PM

Thanks Bill...I've been following those threads...about sulfur denitrators...and I've just about decided to go ahead and buy one of those. It's the smallest "footprint" of any measure that I can take so it looks like that's gonna be my next step.

Savatage · #**954** 06/28/2006, 04:11 PM

Quote:

Originally posted by gotdibz
let me know what your conclusion is

I will do that. If I'm not mistaken, Melvin is the guy to talk to about sands.

I am redoing my RDSB in a couple weeks. I am adding a 3' x 2' x 8" frag tank along side my reef system and plan to plumb it from my return, to the frag tank, to the RDSB, and to the sump. Give me some ideas guys.

bguile · #**955** 07/03/2006, 10:14 AM

I've seen this asked before, but not sure I've seen a response. i'm about to setup my RDSB. Will this create a cycle in the tank? My tank has been up and running for about a month or so now using LR and sand from a mature aquarium running for almost 2 years. It's a 40G breeder and I plan on using a 6 gallon Ocean Essentials salt bucket. Thanks.

DgenR8 · #**956** 07/03/2006, 10:18 AM

The new sand will have to be colonized by bacteria to make it functional, but as long as you are not adding any source of ammonia with it, adding a RDSB will not cause your ammonia, Nitrite, or Nitrate levels to rise.

ziggy222 · #**957** 07/06/2006, 05:52 PM

i was thinking that their would be very little water circulation in a bucket of sand and if the circulation is important?if so,would it be more effective to increase the circulation through the sand?i thought to increase circulation by putting tuffa racks, then screan, then large crushed coral, then screan, then only like a couple inches of sand.or am i not understanding the process correctly?

scrager · #**958** 07/06/2006, 06:00 PM

circulation is important only to keep detrius from settling out of the water into the sand. other than that, you don't need any flow through the sand, just over it.

bguile · #**959** 07/06/2006, 06:02 PM

I think you've misunderstood a little. Only the water flow across the top of the sand should be rapid. Throughout the rest of the bucket it will be slow and that's fine. No special anything else needed. Just make sure the water flows in and out as smoothly as possible and everything else will take its course.

ziggy222 · #**960** 07/06/2006, 06:26 PM

ok thanks guys,that answers alot.so its a very slow process.

dstalfire · #**961** 07/07/2006, 09:33 AM

The results are anything but slow.

ggenz · #**962** 07/07/2006, 08:41 PM

Ok, i have one question about the whole thing,

how does this system (RDSB) not create hydrogen sulfide(eventually)?

could that possibly happen?

or am i just totally off/confused/stupid

neuroslicer · #**963** 07/07/2006, 10:58 PM

It doesn't matter how fast the water is flowing over the dsb... there are always going to be more nitrates in the upper layers of water and near zero nitrates at the bottom... the nitrates will always diffuse down their concentration gradient... continuously moving down deeper in the sand bed where they are eliminated... regardless of flow speed... the dsb is actually drawing the nitrates out of the water as it passes over

it's almost like asking "how can i still breathe oxygen when i have my head stuck out of a car window traveling at 120 miles per hour"

neuroslicer

ziggy222 · #**964** 07/07/2006, 11:34 PM

ok i like that way of explaining it.so they get eliminated under the sand and not trapped?i guess theres no need to replace the sand with new then?you've got my attension now.

neuroslicer · #**965** 07/08/2006, 12:06 AM

Any deep sand bed that has bacteria that can convert nitrates to nitrogen gas will also be producing hydrogen sulfide. the bioconverting bacteria at the deepest part of the sand bed are deprived of oxygen, and in order to produce energy without oxgyen, these bacterial can use sulfate (which is a common ion in sea water but is also found in organic matter (proteins, DNA). it is this hydrogen sulfide which smells like rotten eggs and turns sand black. As long as you don't stir up your sand bed and bring the HS up into the water, you're fine (this would also kill the anerobic bacteria and your sand bed would have to age again to do its work.

The effluenct from a denitrator should have HS in it, but you can slowly drip that into your sump, where it will become oxygenated and converted back to harmless sulface (SO3)

ggenz · #**966** 07/09/2006, 09:57 AM

ohh i see, thank you

so basically, dont touch the bucket

Art_Vandelay · #**967** 07/10/2006, 12:15 AM

One month 5 gal. RDSB w/ MJ1200. No change in nitrates yet

Still 20ppm

Art_Vandelay · #**968** 07/10/2006, 12:16 AM

Thinking about upgrading my skimmer?

neuroslicer · #**969** 07/10/2006, 06:27 AM

I wouldn't expect results this fast... I'm thinking 8 - 10 weeks

Daemonfly · #**970** 07/12/2006, 02:42 AM

Quote:

Originally posted by neuroslicer

The effluenct from a denitrator should have HS in it, but you can slowly drip that into your sump, where it will become oxygenated and converted back to harmless sulface (SO3) [/B]

I'd rather drip this right into a skimmer or a re-gassing tower. The skimmer would problaby be enough though, depending on how much you're dripping.

Laakmann · #**971** 07/12/2006, 02:01 PM

after reading the first 5 pages of this thread I really want to do this, I am going to go out and get a 15-25g storage container at lowes and stick a bulb head in it and tap the line of water going to my refugium

I am going to use about 60lb of argonite sand mixed with play sand, argonite sand will be on top so that this will work as a buffer for my tank also

ill let you guys know how this works but I havnt even set up my tank yet so I am not going to know how big the differance is, just that wether there are or arnt nitrates, if this works Ill have to set up one for my fish only tank also and maybe try it for freshwater with my oscar (biggest nitrate factory ever)

psimitry · #**972** 07/12/2006, 03:34 PM

Make sure you don't get one of the square containers. Apparently, they can't handle the internal pressure and are prone to breaking.

neuroslicer · #**973** 07/12/2006, 05:20 PM

Before you go out and get a bucket of sand to remove nitrates, take a look at this DIY denitrator. I made one using PVC pipe from Home Depot, a PVC gate valve from a local plumbing supply store, a small powerhead pump, bioballs that i no longer used in my sump, and a 50 foot airline coil from Walmart. And it works great and is nice and compact behind my tank (you can see it in the back of my sump in my gallery pic).

http://saltaquarium.about.com/librar...itratornew.htm

Kurt03 · #**974** 07/12/2006, 05:40 PM

Im a little confused about what goes in the pvc tube. This looks like a good idea for people with less availble space. How well has it worked for you and what did you use?

neuroslicer · #**975** 07/12/2006, 05:50 PM

At the very top of the PVC pipe's upper cap, there's an inlet port and an outlet port. I've got a gate valve on the outlet port. Your powerhead delivers water to the inlet port, which is hooked up to the 50 foot plastic coil. This coil goes all the way down to the bottom of your pvc pipe and is open ended at the bottom. Bio balls are packed in the middle of the coil. Here's what happens. The flow rate is adjusted to 1 - 2 drops per second via the gate valve hooked up to the outlet port. Over 6 - 8 weeks, bacteria colonize the tube and bio balls. With such a slow flow rate through the coil, bacteria at the top of the coil will be aerobic, removing oxygen from the water. this water will be oxygen deprived by the time it slowly flows down to the bottom of the coil, so anerobic bacteria (which convert NO3 to nitrogen) will colonize the bottom of the coil. As water leaves the bottom of the coil it slowly flows up through the column of bioballs, where the remaining anerobic bacteria are colonized.

Now you realize that the water flow has to stay slow... if you turn up the water flow then oxygen will quickly get delivered down to the bottom of the coil, killing off your anerobic bacteria, at which point you're no longer converting nitrates to N2.

Sorry to be so long winded, but it's rather complex (and I'm a long winded professor by trade!)

BTW Kurt, wow...! that's a heck of a large sump for a 55 gal tank! great if you've got the room!