sulphur denitrator

[Cal_stir]

If you search SULFUR at BRS you get bio pellets.
If you search SULPHUR at oceansdirect.ca you will see a non-recirculating type sulphur reactor, its made by aquamedic, they do work but because of the low water flow through the unit they are prone to channelling and clogging and can't be controlled with ORP. I think if you shook it periodically and check it daily for a rotten egg smell and adjust accordingly it would be OK.
The rotten egg smell (hydrogen sulphide) is caused when the redox gets below -300mv, and the unit goes anoxic, increasing the flow thru raises the redox and corrects the problem, however, if it's allowed to go more than a couple of days smelling like rotten eggs it can start to poison your tank. The same thing can happen to a DSB in an older tank, but at least you can take the denitrator offline.
If the unit goes anoxic, for more than a couple of days, you have to take it apart, clean the unit and media in ro water and start over tuning it in. Once the NO3 is reduced to nil in the tank, and you get the flow thru rate set to match your NO3 accumulation rate then the unit would be maintenance free except for a periodic shaking to prevent channelling and clogging.

 

[Blob-79]

very good point. One that eveyone with a dsb or rdsb should be aware of. Smell roten eggs=take it offline!

 

[pulpfiction1]

youbetcha

 

[Cal_stir]

Update

OK, I replaced the Caribsea Live Sulphur Media with Mid West Aquatics Sulphur Pearls, I replaced the sponges with screens and added about 1 inch of sulphur, making the ratio of sulphur to matrix 50/50. I put the unit back on line and re-tuned it.
The unit is performing a little better, after a couple of days, I have the drip rate @ 1.5 drips/sec., the effluent NO3 is 0ppm, and the redox is still dropping slowly.
I'm hoping to get 2 dps but I think that that is the most I will get with this size unit, however, the tank nitrates are definitely dropping, they were above 20ppm @ 3 weeks ago, they are definitely below 20ppm now, it's hard to give an axact number with the colour chart.
Although it is a slow process, it is working, it eats nitrates faster than they accumulate.
I think now that the key is patience. I,m going to control the redox between -150mv and -200mv and leave the unit alone, I'll check my nitrates weekly and post the results, I think the tank will be at 0 NO3 in 8 to 10 weeks.

 

[pulpfiction1]

sure sounds promising,i see you said "sulphur to matrix 50/50" i take it your using matrix as well.from what i read on thier site(Seachem)long ago that matrix is also a nitrate eliminator.is this new addition as i didnt read that in earlier posts or am i not understanding you corectly?

 

[Cal_stir]

not new, I originally had a 60/40 split, 60% seachem matrix bio-media and 40% caribsea LSM, the matrix is in the bottom half of the reactor because you never have to do anything to it, periodically ( @ 2 yrs ) you have to add sulphur. the caribsea ARM is run in a seperate reactor so you can replenish it without disturbing the main reactor, ( @ 3 months ).
I've heard there are some better bio medias out there, ceramic I think, but the matrix works fine, you don't want the unit too big or you have to downsize it once the tank reaches 0ppm NO3.
From what I understand, the sulphur feeds the aerobic bacteria, that eats the O2, causing the redox to drop providing an enviroment for anaerobic bacteria to live that eats nitrate, however, if the redox gets too low, -300mv and below, then the reactor goes anoxic and converts nitrate to ammonium, which causes the reactor to become a nitrate factory. If there is not enough nitrate to feed the anaerobic bacteria, then it dies off , causing a "rotten egg" smell from the reactor, the same things can happen in a DSB.

 

[Cal_stir]

Update

The denitrator is functioning well, operating at 2 dps, effluent NO3 is 0ppm ( API, and Salifert ).
Tank NO3 is less than 20ppm API ( can't tell accurately as 5ppm and 10ppm look the same on the color chart and there is no 15ppm )
Tank NO3 is 5ppm Salifert, which I believe is a more accurate test kit.
Tank NO3 was 25ppm Salifert before I built the denitrator, I used the API test kit during the build process because I had it and didn't want to use up my Salifert kit doing the dozens tests required.
Redox is being controlled at -175mv.
The cheato in my gium is starting to turn white, I am also running GFO in a phosban reactor.
At this rate, I expect the tank to be at 0ppm NO3 in another week or two.
I have stopped dosing kalk and calcium as my ca has shot up which I think is due to the extra ca from the ARM ( calcium carbonate ) media that the effluent passes through before entering the tank.
So far my only disappointment is the mag-drive pump I used, it's noisy and I had to silicone the cover on to stop it from leaking, I'm affraid it's going to leak again.
I still do a monthly 10% water chg and vac as always.
I will post again when I have more results.

 

[pulpfiction1]

looks like its goin decent,i hear ya on the mag drive pumps,got a couple of mag 18's and both are noisy,even more so when used externally.awhile back i hade my cheato turn white so i removed it.thought maybe the vodka had something to do with it.my NO3 is back up tp 20ppm.i think its because i removed the cheato so i am gonna put some back in.PO4 is also slightly elevated.gonna do a small water change today.

 

[Cal_stir]

I have read that the cheato requires nitrates to do well, my denitrator research shows that the cheato dies after nitrates are gone.
you may have to harvest more often to keep the amount of cheato in proportion with your nitrates.
I find that if you keep the cheato in a bucket of tank water, with some ambient light, it will keep quite a while.

 

[Cal_stir]

Update

been running 10 weeks now
definately stronger with the sulphur pearls verses the caribsea Live Sulphur Media

drip rate is 3dps normal
6dps when redox is below -175mv
average redox is @ -170mv
stopped testing the effluent as it is always 0 NO2, and 0 NO3
tank is less than 5ppm NO3 API, and less than 5ppm but more than 2.5ppm SALIFERT
other than a couple tweeks of the driprate, i haven't touched the unit for 2 weeks now
have not noticed any adverse affects
i am very happy with the unit  ;D
here' a few pics

 

[pulpfiction1]

looks intense,glad your finally getting the results you were after,i hope they are good over an extended period of time

 

[Cal_stir]

update

the denitrator is getting stronger, drip rate is almost a steady stream, tank nitrates are 1ppm salifert.
i would not try this without an orp controller.
the denitrator also acts as a calcium reactor, i have stopped dosing calcium and kalkwasser and the denitrator is maintaining my calcium.
i still dose alk, mag, and strontium at the same rate as before.

 

[teebone110]

Cal,

Congratulations, mission accomplished! 8)

 

[Cal_stir]

Thanks Teebone

I was a bit apprehensive at first, it seems that everything you read about in this hobby is a 50/50 chance that it will work.
What works for one person doesn't always work for another, I think the main problem is that some people just don't have enough patience, they expect every thing to happen fast.
Again, my only regret is the mag3 pump I used, I think I will be swapping that noisy piece of crap out soon
The unit cost me about $500. to build which includes the $200. orp/ph controller, money I consider well spent considering I'm in this hobby for the long haul.

 

[pulpfiction1]

great goin,keep posting results for me please,want to know how it goes over a longer time frame

 

[Cal_stir]

will try to post something monthly, if you're curious to how it's going or have any questions, pm me.
the guy i got alot of my info from has been building and using sulphur denitrators for over 20 yaers.

 

[pulpfiction1]

i appreciate that,this is quite the setup you have and runs good,myself ,i need more info and your results will sure help

 

[teebone110]

Hey Cal,

Quick question for you.. What is the total size of your sulphur denitrator? Can it be modified to fit under a tank inside a stand? How much room do you need? Thanks.

Tyler

 

[Cal_stir]

mine is 30" tall, but height was not an issue with me, the reactor i used was 14" tall and i could have easily made the unit about 16"tall.
the footprint is 6"x10"

 

[teebone110]

mine is 30\" tall, but height was not an issue with me, the reactor i used was 14\" tall and i could have easily made the unit about 16\"tall.
the footprint is 6\"x10\"

That is good to know. I think I can squeeze that footprint under my stand if needed!