ULNS - Denitrators
 

What's the best option for keeping Nitrates near 0?

I have been cruising the web for ways to limit nitrates in my setup. I like the idea of ULNS, but don't like the idea of Zeovit for two reasons (I could be very wrong, so please correct me): by targeting the ammonia/ammonium, the tank is effectively not cycled, meaning there is no easy way off the system without a cycle/crash; dosing unknowns without testing and watching for changes to corals is not measurable enough to give me any sense of comfort.

As I understand it, this leaves few options if I want to keep nitrates near 0.2ppm: huge daily water changes; deep sand bed; bio pellets, carbon/coil denitrator, or a sulfur denitrator.

I have tried to find out why sulfur denitrators went out of style, or never caught on in the first place. If anyone can help me figure this out, I would appreciate it. I can't find too many down sides to them, aside from having to monitor pH, dose Alk, and keeping an eye on ORP values on the aquarium and effluent as a method of monitoring the viability of the bacteria within.

I can anticipate similar potential issues with the bio pellets (unstable and aerobic makes potential crashes more likely) and the carbon/coil denitrators (require specific dosing of a carbon source), but still don't understand why they haven't caught on as well?

If anyone can shed some light on this, I would greatly appreciate it.

I don't know much of denitrators however, I am a firm believer in large wc and vacuuming the sand bed. You may want to target .1 or .2 nitrate level instead of 0 and I also recommend keeping your phosphate levels in check as well.

Thanks for the post... I think there are a lot of people in the same boat, not knowing about denitrators. I suspect that's for a good reason that I just can't figure out yet. I agree with the water changes and vacuuming.

FYI:

Targeting 0.1-0.2ppm, currently running GFO to keep phosphates <0.03ppm, and ideally lower.

I also plan on doing a 15% WC weekly, which I hope to turn into a 15% continuous water change... but that's for a different thread.

Also, I am just wrapping up the cycle, so my bio-load is nil. I just was researching ZEOvit and because they recommend starting it on a new system, and I like some aspects but not all, so I hoped to compromise with a denitrator.

I can't find too many downsides on the web, but they are rather unpopular, so that must be for a reason.

The best method for keeping nitrates near 0 is a well set up tank with sufficient good quality live rock to support the bio-load. This is also the most bulletproof. Keep it simple!

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Agree! wc is to reduce and maintain along with good skimming.

How does the size of my filtration system control Nitrates? Aren't nitrates the end of the nitrogen cycle? I understand how LR can control nitrites, by converting them to nitrates, but from there I am lost.

Nitrates are consumed by the anaerobic bacteria in the low oxygen area inside the rock.

Really? That's a great suggestion. It must operate similar to a deep sand bed. I bet you need a ton of live rock and very little flow to make that happen. It sounds like its not something for a display... I think I have seen that setup at Wai's in Calgary. He has a SH Ton of LR in a ~300Gallon with very little flow.

Has anyone had success maintaining 0.1ppm Nitrates with 10-15% water changes weekly with a setup like this?

I doubt I have enough space to setup another aquarium for LR for my 700gallon total volume system. Unless this doesn't take as much real estate as I am thinking.

Thanks again for the info.

I don't believe that there is such a thing. :-). There are lots of options, all of which you seem to be aware of already.

Maybe set up a poll to see which of the ones you listed seem to be the most trendy these days.

b09u5,
Both coil and sulphur denitrators went out of style because they were prone to clogging or when vunerable to power failures, gave you an H2S problem.
Maintaining a slow constant flow was critical with them.
Follow the suggestions everyone else here has listed and you should be fine.

Google "berlin method"

Thanks kein,

I might just take a poll. All I am really looking to know is more of what Mitch is getting at.... the drawbacks of the older denitrators. (Thanks Mitch, those are the pieces of the puzzle that I am missing - along with a few more i bet!)

So far, I hear that they can plug and cause H2S issues and power failures. Other than that, I hear they could keep Nitrates <0.05ppm. If those are the only two drawbacks, and I could solve them, ie: run effulent through GFO to remove the risk of H2S and have the intake line kept open with power (shuts down without), wouldn't that be a good thing?

Or am I a noob, over engineering/overthinking this hobby?

OH NOES.

kIen,

My apologies.

If you go to my tank journal link at the bottom, you will find that I initially battled very high nitrates before finally resorting to bio pellets. Have been running with zero nitrates for about 2 years now, and have not had to open my bio pellet reactor since Nov 2012, more than a year ago.

Refugium, anyone?
 

I'm surprised nopbody mentioned a refugium so far. It's all about reactors, denitrators, etc. Plants will remove nitrates very efficiently. And when I say refugium, I don't mean an afterthought, like a ball of cheato in the sump with a small lamp above. I mean a tank plumbed inline with the display tank with macroalgae to suck the nutrients out of the water column.

Another solution is an algae scrubber. Whether it's a waterfall style (in the sump) or upflow type, it's not that relevant, they are both good means of nutrient export.

I have an inline refugium behind the DT with a small chamber in it where I run an upflow algae scrubber. I have to go and prune it weekly, but my nitrates are undetectable. For phosphates I run Rowaphos, but that's another topic altogether.

I tried that, as per my journal,... didn't work. I think refugiums are fun to do, and work if your nitrates are not that high to start with. But for serious and guaranteed nitrate control, can't beat bio pellets.

agreed:)


plants will only absorb so much , on a 10g tank its fine but on larger system with high bioloads carbon dosing is the way to go:)



have you thought about VSV? some of the older school methods are still the best today;)

I have about 200g total water volume, maybe 100 pounds rock. I also run zeo part time. Meaning I forget to do anything with it for months at a time, which translates to "you can quit anytime you like".
I have never had measurable NO3 in 4 years. I attribute that to quality rock that I keep clean with lots of flow. I also have near 0 coralline on the rock, which IMO plugs up the pores reaching the anaerobic bacteria.
I change about 25% water volume bi-weekly and have never vacuumed my sand bed. Seems easy enough to me :)

You don't have to vacuum with sugar sand... :twised:

True, it's self cleaning!!

I had never heard of VSV dosing before. I'll look into it.

Reef Pilot, It's good to hear that some people run these types of reactors and haven't had stability issues. Funny enough, out of all of the options, the bio pellets worry me the most. BTW, I checked out your tank thread and it looks awesome! I hope to still be in the hobby in 10 years!

Anyone else have a denitrator of any kind?

VSV is also effective and good way to start before spending hundreds of dollars on the blue bottles. :biggrin:

Just to be clear, I inherited that 10+ year tank when we moved, so my time in the hobby has been since then.

Bio pellets work well, if you start slowly and use MB7 (to prevent cyano). Once the nitrates are down, the reactor is in maintain mode with very little bio pellet consumption. Like I said, have not had to add any pellets for more than a year. Was every few months the first year.

:razz:

nitrate
 

i built my own coil nitrate reactor a couple of years ago.it has clogged but i just blow it out.i'm planning on modding it so i can remove the top and change out the inner's every 6 months or so.my nitrates are 34 ppb on a hanna checker

nitrate
 

sorry .034 ppm.water change every sunday(10%)

So it looks like there are people that run denitrators and love them. With that said, there are lots of crack addicts too. Here is what they have to say:

http://www.maast.org/showthread.php?...hur-Denitrator

http://www.3reef.com/forums/general-...l#.UyPtzF6H_aU

Another option for nitrates seems to be mixing kalkwasser with vinegar rather than water when dosing for calcium and alkalinity. I am not sure if this would keep up on large demand systems, but it's interesting for sure.

http://www.reefscapes.net/articles/b...alkwasser.html

Or you could use live rock and water changes :)

I suppose you are probably right, I will use likely leave my setup as is, and do my weekly water changes. I will test for nitrates and if I cannot control them at the ultra low levels that I want to see, I will look into something else.

This could be overkill.

Aquattro, what levels are you able to keep your nitrates at keeping it simple with LR and water changes?

I've never had levels I could measure. Now as I posted earlier, I have a zeo reactor with those cute little rocks, but on average I have changed them 3 times/yr.
I do feed liberally and have minimal cleanup crew (need to increase this, I think).
But in reef keeping, as all things in life, start with the simplest approach, and add complicated as required.
IF good rock and water changes don't do what you want, only then should you worry about how to control it. Jumping right into a denitrator might be starting from the wrong end of the problem.

I also think I will setup a poll, What's your ULNS nitrate level, what are your methods of maintaining the ULNS nitrate level?

workin on it

Oh good, we never have enough polls :)

I think that's a great idea. Things like this tend to change over time so I totally think constantly taking polls on the subject is a good way to gauge where people are at currently. It's like lighting. 10 years ago if you took a poll most people would be using halides (probably)? Five years ago you'd see a huge shift to T5s, two to three years ago up until now you'll see the results change again as people shifted to LEDs and if you took the poll now I bet we'd see some very interesting results as people are trying to figure out hybrids or possibly ditching LEDs altogether.

ultra low is very hard to do and requires alot of work to get to , just doing water changes rarely gets you there , thers a diff in low range and ultra low range. to get to ultra low range your probably going to have to carbon dose.


its simple but should note that if you have a nitrate level then you arnt ultra low ,in ULNS on lab grade test kits nitrates arnt measureable barely in the PPb so once you get to a ulns system algae cant survive, corals need supplements and the tank is purely sterile.

i would read about the diff between in both before going into to it too far as keeping a tank healthy at ulns is hard to do and needs certain requirements to keep it alive:)

personally i think low range is good enough for what most of us want to do:)

he speaks the truth! In fact, I recall reading that the ocean reefs do not operate in a truly Ultra Low Nutrient environment like we often try to achieve. That is, they have measurable nitrates! The reason we do it is so that we starve out the browning zoanthellae within the coral so that they eject them. This results in paling. To counter this you have to feed them with amino acids and various other supplements to maintain colour. It's a very delicate balance act. Stave them then feed them just enough so that they look super awesome. Many corals in the ocean reefs are naturally not as colourful as what we see in ULNS reef tanks.

yeah its a teetor totter (?) and delicate , so some steps need to be taken to keep them stable.

like i say though i dont find the need t go ULNS you get great colors, growth and overall livestock health is just fine in a low range system:)

youll still be nil for nitrates but at least its not sterile inda nil lol:)

I use Prodibio (just the main three) and I live just on the border between really low and ultra low. I also have to do very little in terms of maintenance. I will say that I cut back reefbooster to almost nothing and before I knew it my corals lost color and were starving. Since going back to their recommended dosing colors are coming back. I feed quite a bit and have to use gfo to keep phosphates in check.

A low nutrient system is the healthiest for corals, and the most stable. Undetectable nitrates and phosphates are easily achieved with live rock and GFO. I think of ULNS corals as being like super models. Nice to look at, but under fead and walking a fine line between life and death.

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