DSB in a bucket for nitrate control

[ggenz]

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]

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]

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]

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]

ohh i see, thank you

so basically, dont touch the bucket

 

[Art_Vandelay]

One month 5 gal. RDSB w/ MJ1200. No change in nitrates yet Still 20ppm

 

[Art_Vandelay]

Thinking about upgrading my skimmer?

 

[neuroslicer]

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

 

[Daemonfly]

<a href=showthread.php?s=&postid=7701589#post7701589 target=_blank>Originally posted</a> 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]

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]

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]

Alternative to a bucket of sand!

Alternative to a bucket of sand!

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/library/blank/bldondiydenitratornew.htm

 

[Kurt03]

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]

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!

 

[Kurt03]

ok was just trying to figure out were the o2 was being used up, and its actually inside the tubing. Has it worked well for you?
About the sump, its worked out well, i have a closet right next to my tank so i just plumbed it right to there and now i have plenty of room
Now if i can just find where to put either my DSB or this Denitrater.

 

[neuroslicer]

Earlier this year I had been using a Hagen NO3 test kit which was reading ~10, and when I bought a new kit (salifert) it read 50! Turns out the Hagen reagents were old. Rather than be scientifically systematic, I changed several things at once: added a chaeto/mud refugium (see gallery), added the denitrator, added a UV sterilizer, upgraded my skimmer (aquac urchin pro)and most recently added a phosphate reactor. My NO3 and PO4 are barely detectable now. I alternate a very small amount of phosban and run it for ~3-4 days before I switch it out for carbon... you have to watch your alkalinity with phosban. Coral are growing better now and the tank is purpling up faster than ever before!

 

[Daemonfly]

The problem with de-nitrator coils is getting them tuned correctly. You need the proper flow rate for them to work right, proper length of coil, etc... There's been lots of threads on these. They do work, but require more work in setting them up & keeping them running properly.

Buckets are easy in their implementation as you just need to have clean water flowing over them.

 

[ZenMan]

Is there a limit to the depth of a RDSB? I'm thinking of plumbing to my basement where I could use a 55 gallon Plastic Drum for a RDSB. If I filled this with silica sand (We don't have access to Southdown or equivalent sands here in Colorado), would it work okay, or should I limit the depth of the sand?

Thanks for any insight.

Jeff

 

[Kinetic]

For a 40g display and 30g sump (about 70g of water volume) what dimensions for a RDSB would I need?

 

[scrager]

depth was just covered on the last page. you need about 18-20 inches. any more is really just a waste of sand, but won't hurt anything.

Kinetic: start with a 5G bucket