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FAQs on Marine Water Quality involving Nitrates: Chemical Filtrants

Related Articles: Carbon Dosing; An Effective Means of Phosphate and Nitrate Control, by James Gasta, Nitrates, NitritesAmmonia, Phosphate, SilicatesNutrient Control and ExportDeep Sand Beds

Related FAQs: Nitrates 1, Nitrates 2, Nitrates 3, Nitrates 4, Nitrates 5, Nitrates 6, Nitrates 7, Nitrates 8, Nitrates 9, Nitrates 10Nitrates 11, Nitrates 12, Nitrates 13, & FAQs on: The Actual Science Re: NO3 Compounds, Importance, Sources, Means to reduce: NNR (Natural Nitrate Reduction, Anaerobic Bacteria), Algae, Other Biota, Physical Filters, Chemical Filters... NitritesAmmonia, Establishing Cycling, BiofiltrationPhosphate, Silicates, Biological Filtration, Fluidized Beds, Bio-Ball, Wet-Dry Media 1 Denitrification/Denitrifiers, Wet-Dry Filters, RO./Distilled/Treated WaterChemical FiltrantsDeep Sand Beds


media reactors     9/11/14
I have a 90 gallon reef with persistent problems with phosphates and nitrates.
<? Search, read on WWM re>

We are trying to decrease our feedings ( have read much of your recs on this)
amount but have also purchased a phosban 150. Could I run 2 of these in a series ( as opposed to parallel) configuration with different media?
<Yes; you could... not the route I would go though... better to have a "sailboat" vs. "motor-cruiser" approach... DSB, biological means of export, competitors, predators of these... Bob Fenner>
thanks js

Sulphur denitrifier, use with sulphur, or bio pellets?   11/17/13
Hi Bob,
?????????? I am hoping you can help me once again. I have a 180 gal FOWLR that's been running for about 18 months. It?always has high NO3, fish are well fed and healthy but I would like more control of NO3 than reduced feeding and big water changes would give me. I have tried carbon dosing for several months now without change
<Doesn't always "work"... only in/w/ systems that are carbon deficient>
in my parameters using Red sea's Nopox liquid, I read people have success
with carbon dosing sooner than this, but I have not been so fortunate. I have two skimmers running in my sump, Red sea's C-Skim 1800, and an old turboflotor 1000 which uses ozone, plus?plenty of live rock so it should work. The skimmers certainly pull out plenty of skimate.
?????????? I have an old Korralin sulphur denitrator from an old tank currently in?storage.
<I'd get it out; try using it here>
 It was fiddly to operate and sometimes smelly, but good at reducing NO3, though I was always worried about the acidic effluent affecting alkalinity.
I am debating?if I should resurrect this denitrator?for my current tank.
The denitrator?recirculates tank water within itself via a pump, but?has a low flow rate in and out for the anaerobic bacteria it utilises. I was wondering if I could use bio pellets with this denitrifying filter instead of sulphur.
Would that work?
Are bio pellets preferable to sulphur denitrification??
<... depends on the make-up of the system, cause of issues... the two mechanisms mentioned are not dependent on each other... Operate independently. Sort of like asking re using a bike to get about vs. using a blender to make a drink>
Would be interested and thankful for your advice,
<?Bob Fenner>

Nitrates, sadly yes.      4/16/13
Hi Crew,
<Hiya Adam>
I was wondering if you have heard of any success with Seachem's Denitrate, mine are at 20ppm which I know is not a major problem but I am worried they will increase.
<What size tank do you have? Salt or Fresh? Livestock? I've used Seachem's Denitrate, Matrix and Pond Matrix all with success. The particle size of Denitrate is a bit small for biomedia imo. Keep in mind that the method in which you run these is paramount like most other forms of bio media>
I had hoped that by adding Purigen they would not increase which so far they have not and with the addition of Alpha the anaerobic bacteria would be able to break down the existing levels. At best I think that I have achieved a stand off for about a month now but want to tip the scales in my favour, aiming for 5PPM.
<Goals are key. haha So tell us a bit more about your setup. Details details. How large are your water changes and how often are you doing them.
Filtration?? Purigen is some nifty stuff but imo is a bit too pricey but has its occasional application. I tend to prefer matrix over Denitrate as it is a happy medium (haha medium) in size.>
Regards, Adam.
<I share your goal. Provide some more details and we will get your nitrates sorted out no problem. -NateG>
Re: Nitrates, sadly yes.     3/17/13

OK I'll probably take a gamble, I read the Denitrate is better in slow moving water which is my case. The tank is marine and all fish are fine I just want to avoid problems rather than treat them
<I would think that Denitrate would be better for fast moving water.
Although it may have greater outside surface area. When you consider that the entire medium is porous in itself I wouldn't think size should matter as far as biological filtration efficiency. I do see Denitrate having an easier time trapping junk in which case it may better serve as a high flow media. And the larger the size being better for the slower the flow.
Re: Nitrates, sadly yes.     4/19/13

I thought slower rate please find info on Denitrate from Seachem's website "For best results, de*nitrate™ should be placed to assure the flow      of water through it, such as in a canister filter, chemical filtration      module, or box filter. Flow rate should not exceed 200 L (50 gallons*)      per hour. If higher flow rates are unavoidable, use Matrix™ or Pond      Matrix™.
<I wouldn't recommend running Denitrate in a filter bag sitting on the bottom of a sump. Asking for trouble in the long run>

Mail, HPO4 product /Tropic Marin  -- 12/19/11
<"Is not a doser, an additive. I will send Bob any further input I may have on this product for posting in our Daily FAQs. <<None>>
This likely will not occur for a couple of months. Do inquire at that time as we do not store/save queriors email addys.
James (Salty Dog)>"
I'm reading this as you do not want any further input on the product...
<Mmm, meant only that I had no further input at present. B>
re: Mail -- 12/19/11

OK, didn't think you wouldn't want any info so I just wanted to be sure.
<Ahh, sorry for the confusion, lack of clarity. More info./data the better!
re: Mail -- 12/19/11

OK, I'm going to continue using this product for another month and then do another NO3 test and will report the results.  I've also got additional information coming from Lou Ekus (Tropic Marin) which I will include.
<Real good>
Re: Marine Actif -- 12/19/11

Hi Bob,
Here is the response I received from Lou re a question I had regarding Marine Actif.
<Thank you. Will accumulate/share. B>
Marine Actif -- 12/19/11

Hi Lou,
I'm trying the subject product and so far it looks very promising.  My NO3 was at 15ppm when I first dosed Marine Actif and in just a little over a week, it has dropped to 10ppm.  Didn't think the product would work that fast.  I also noticed improved water clarity.  I've been suggesting this product to our readers in lieu of fiddling with reactors and polymer beads.
The product is also reasonably priced.
I have one question on the product.  With reactors/polymer beads, overdosing causes cloudy water caused by an excess of bacteria.  Does this hold true with Marine Actif?  Can oxygen levels decrease if not dosed properly as can happen with polymer beads?
Best regards,
James Gasta
Wet Web Media
Re: Marine Actif -- 12/19/11

Hi James,
Here is what I think are the answers to your questions...
A dosage up to the recommended dosage each day or a single dosage of twice the recommended dosage did not cause clouding by bacteria in our aquaria. We also did never heard anything from any users about clouding by bacteria caused by normal recommended dosing of REEF ACTIF.
Since REEF-ACTIF is degraded by aerobic bacteria  it has to decrease oxygen levels but we also have never observed adverse effects or oxygen levels that are dangerously low.
I hope this helps. If you still have any questions, just get back to me and I'll get answers for you if I don't have them.
All the best,
Lou Ekus
Director of US Operations
Tropic Marin USA

Re Powerheads 10/6/09
Guess 2  #3's are better than?
<Better than what, or did you mean better then.  The Koralia 3 would be my choice for a tank with your dimensions.  James (Salty Dog)>
Re: POWERHEADS 12/16/11

any info on aquaripure.. does it work in saltwater tank?
<I have no experience or knowledge with that product.  Best to ask this on a forum, get users comments.  James (Salty Dog)>
Re: POWERHEADS 12/17/11... actually an alcohol-fed Denitrator brand    12/17/11

It's a filter that removes nitrates(injecting 7ml of vodka) running water through tube removing oxygen. Made by Aquaripure.
<Ah, a carbon doser.  May want to check out Tropic Marin's new product called Marine Actif.  It accomplishes the same thing but with no filter/reactor to fiddle with.  I am currently trying this product and it looks very promising.  My water has gone to the next level of clarity while nitrates are slowly decreasing.  James (Salty Dog)>

Re POWERHEADS 12/18/11 NO3 reduction/ants

please keep me posted on this doser
<Is not a doser, an additive.  I will send Bob any further input I may have on this product for posting in our Daily FAQs. <<None>>
This likely will not occur for a couple of months.  Do inquire at that time as we do not store/save queriors email addys.
James (Salty Dog)>

Dosing Nitrate...? 11/4/11
Hello guys,
<Hi Steve>
I have heard of Nitrate dosing for aquaculture of clams and I have also heard of very small Nitrate dosing to help bio-pellet reactors to raise the Nitrogen ratio high enough to allow the bacteria to propagate. Does anyone know what form of Nitrate can be used and how much?
I'm assuming Potassium Nitrate but I'm not sure.
<Bio-pellets actually feed nitrate consuming bacteria by providing a carbon source and dosing nitrate will just increase the bacteria population which will gobble up nitrates. Adding/feeding a few small fish in the aquaculture system should provide all the nitrate necessary for clams. A level of 5-10ppm NO3 would be fine.>
<You're welcome. James (Salty Dog)>
Re Dosing Nitrate...? 11/4/11

I guess I need to clarify. I have a number of customers with bio-pellet reactors and they have brought the Nitrates to zero. The problem is that with zero Nitrate, the Carbon and Phosphate cannot be assimilated by bacteria.
<Carbon feeds the bacteria which in turn feeds on the nitrate and phosphate If there is a lack of one or the other, the bacteria population lowers based on the food supply. Dosing nitrate will increase the bacteria population as long as carbon is present. Why would one want to take the nitrate to very low levels and then want to dose nitrate. Doesn't make any sense to me unless I'm way off base somewhere and Bob can input here.>
The systems are Nitrate-limited. As I'm sure you know, there must be Carbon, Nitrate, and Phosphate in a ratio of 105:16:1. If any of these molecules are limited, bacterial reproduction cannot happen.
<Your reference to the Redfield Ratio (105:16:1) may be steering you wrong.
This ratio is found in both bacteria and phytoplankton and is close to the ratio of the same elements in seawater. If there is an excess of either nitrate or phosphate, then the limiting factor must be the lack of carbon.
Bacteria, like phytoplankton, consume these elements for growth and reproduction and the Redfield ratio is not necessarily a strict ratio to follow in closed systems.>
I need to dose Nitrate so that the bio-pellet rector can do it's job.
<It is doing it's job if nitrates have been brought to zero.>
What form of Nitrate? I read that Anthony Calfo doses Clams in his South Pacific aquaculture facility.
<<He has no such facility...>>
<Likely because clams do better with small amounts of nitrates in the system. If your concern is having small amounts of nitrate present, lower the carbon source.>
Can you help out?
<I did. James (Salty Dog)>
Re Dosing Nitrate...? 11/4/11

Maybe I'm not making myself clear. The bacteria need all three molecules to reproduce and typically, Carbon is the limiting molecule.
<You made yourself very clear and I understood and responded accordingly.>
The system I'm working on currently has zero Nitrates. As long as there are zero Nitrates, the bacteria cannot utilize the available Phosphate because now, instead of there being a shortage of Carbon, there is a shortage of Nitrates.
We don't really even need to debate this point. The question I want <is> an answer to is what form of Nitrate is typically used in Aquaculture?
<You may want to try your thought of using potassium nitrate as it is a very good source of nitrogen and is the primary ingredient in marine plant food.
May want to look here. http://live-plants.com/plantfood.htm
<You're welcome. James (Salty Dog)>

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