How long for Nitrates to go down?

[sarah_nick]

Hi,

 

My 8g nano has been set up for 1 month as of today. All the readings are fine, aoart from Nirates which are always at 20.

 

I'm using an API Test kit and have checked and checked again that the I'm testing right and that the readings are correct.

 

I had a sponge and ceramic rings in the filter.... these were removed yesterday after doing lots of research and now it's just filter floss. Carbon will be added as soon as I can get to my LFS.

 

I have 3 kilo of live rock, live sand, and use live (bought) water. After doing 3 30% water changes the nitrates have not reduced. Am I expecting things to happen too soon? How long should it take for them to reduce even though I am using all 'live' products?

 

Thanks

[supraeli]

nitrites or nitrates? nitrates are not reduced in closed biological systems unless they are massively sized for nitrogen gas production through anaerobic metabolism. nitrates can only be reduced through nitrogen fixation during photosynthesis or water changes. sponges and floss can trap detritus which will decay further into nitrate as a product - change these often if you choose to use them.

 

good luck

[vangvace]

sounds like you still cycling. Stay the course

[ballerina]

adding chaeto, a macro algae, will also reduce your nitrate levels.

[sarah_nick]

It is Nitrates.

 

I would have thought after 1 month my cycle should be nearly finished, plus there are no spikes it's just contantly at 20.

 

I have thought about adding chaeto - but how long is a reasonable time to wait for the nitrates to reduce on their own?

[Jusiko]

If you don't have anything in your tank to fix the NO3, it will stay at it's current level (subject to water changes). You'll want to get a little soap dish and some chaeto, and just hang it on the side of your tank. A month is more then enough time to wait for chaeto, as it's a pretty hardy algae and a staple for most peoples' tanks.

 

Since your NO3 is constant, your cycle is essentially over. Biologically speaking, your tank is now processing all/any waste being produced in the tank, and spitting out the final product, NO3. Put in something to mop up the leftovers via photosynthesis, continue w/ testing, and everything will be fine. You'll probably want to ease your water changes slowly down to 15%-10% as well.

[vangvace]

Nitrates take the longest to come down. How long of a time delay between water changes? Water source?

 

I'd take a water sample to a fellow reefer or the lfs to verify your test kits readings.

 

Have you had a diatom bloom yet?

[masterbuilder]

Well.... I do it different than the other posters. At the end of the cycle in tanks I have had, I do this:

 

50% water change, a week later I do another 50% water change. That will bring down the nitrates by 75% or slightly less since nitrates are being produced all the time. Then wait a few days and add my CUC and start my normal weekly water changes of 20-25% from then on. IMO, the most effective way to reduce nitrates is through water changes. It has always worked well for me....but...there are a 100 ways to skin this cat.

 

EDIT : This is all using R/O or Distilled Water. Never tap or ANY other kind of water.

[lakshwadeep]

Nitrates can and should be able to go down on their own in a tank with normal water changes. Your live rock should be able to do this on its own, as long as your bioload is within normal limits.

 

edit: Jusiko: I think you're meaning "NO3" instead of "Na" for nitrates.

[sarah_nick]

Thanks all.

 

'Jusiko', I think I will get some chaeto now - thanks.

 

'vangvace', it's about 3-4 days between water changes, I buy my water from my LPS. It's called Nutri-SeaWater which is natural live ocean seawater. They have a website which is www.naturesocean.com. Is the diatom bloom where you get the brown algae across the sand - if it is, yes.

[ballerina]

Thanks all.

 

'Jusiko', I think I will get some chaeto now - thanks.

 

'vangvace', it's about 3-4 days between water changes, I buy my water from my LPS. It's called Nutri-SeaWater which is natural live ocean seawater. They have a website which is www.naturesocean.com. Is the diatom bloom where you get the brown algae across the sand - if it is, yes.

 

yes it is that brown algae across the sand, but it also will grow all over your rocks.

[smedge]

Wow... the amount of misinformation posted here gets to me sometimes.

 

Here it goes:

 

Nitrate levels are not watched to determine when the cycle is complete.

 

Ammonia and NITRITE levels are monitored to determine when the cycle is complete. When both have zeroed out the cycle is over, done, cya (regardless of nitrate levels). Neither should be present after the cycle unless there is a problem with your biological filter.

 

Nitrates constantly build in a normal aquarium at a rate depending on your bioload (how many organisms you have in your tank). Nitrates have to be removed completely differently than ammonia and nitrites. The most common ways are:

 

1) water changes.

2) photosynthesis via a macroalgae.

3) chemical filtration (ion exchange resins and the like [chemipure, denitrate, etc...]).

4) denitration in a deep sand bed or other anoxic area in the aquarium (like in live rock). Don't try this unless you REALLY know what you are doing (i.e. the dangers of nitrite contained in a deep sand bed).

 

So in short... your tank is finished cycling. Use the above mentioned methods to reduce nitrates. I listed them in what should be your order of preference (and I probably should have left #4 out, but I was being complete). Get hoppin' with those weekly (initially) or biweekly (later on) water changes. Reducing nitrates is one of the primary reasons you are doing them.

[sarah_nick]

yes it is that brown algae across the sand, but it also will grow all over your rocks.

It did grow on the rocks too, but not much - it's virtually all gone now, there's a tiny bit left on the sand.

[sarah_nick]

Wow... the amount of misinformation posted here gets to me sometimes.

 

Here it goes:

 

Nitrate levels are not watched to determine when the cycle is complete.

 

Ammonia and NITRITE levels are monitored to determine when the cycle is complete. When both have zeroed out the cycle is over, done, cya (regardless of nitrate levels). Neither should be present after the cycle unless there is a problem with your biological filter.

 

Nitrates constantly build in a normal aquarium at a rate depending on your bioload (how many organisms you have in your tank). Nitrates have to be removed completely differently than ammonia and nitrites. The most common ways are:

 

1) water changes.

2) photosynthesis via a macroalgae.

3) chemical filtration (ion exchange resins and the like [chemipure, denitrate, etc...]).

4) denitration in a deep sand bed or other anoxic area in the aquarium (like in live rock). Don't try this unless you REALLY know what you are doing (i.e. the dangers of nitrite contained in a deep sand bed).

 

So in short... your tank is finished cycling. Use the above mentioned methods to reduce nitrates. I listed them in what should be your order of preference (and I probably should have left #4 out, but I was being complete). Get hoppin' with those weekly (initially) or biweekly (later on) water changes. Reducing nitrates is one of the primary reasons you are doing them.

 

Thanks

 

What particular mis-info were you referring to?

 

Going to do option 1 & 2 - keep up with the water changes but get some chaeto to help with the nitrates.

[lakshwadeep]

Umm...smedge, you also have provided misinformation. Sorry if this is harsh, but using a didactic tone means you should double check what you're saying.

 

First, you can't just stick corals or fish (except for damsels, et al.) with very high nitrate levels. I don't think the semantics of a cycle strictly mean when ammonia and nitrites become zero. Besides, the fact that a test shows zero just means that the bacteria have caught up with the die-off, not that the die-off itself has stopped (other wise the nitrates would be lowering also).

 

As I have said before, denitrification is a process that can easily be established with even a small sand bed and the rocks. Also, the denitrifiers are often anaerobes who often can switch between aerobic and anaerobic respiration.

[supraeli]

Umm...smedge, you also have provided misinformation. Sorry if this is harsh, but using a didactic tone means you should double check what you're saying.

 

First, you can't just stick corals or fish (except for damsels, et al.) with very high nitrate levels. I don't think the semantics of a cycle strictly mean when ammonia and nitrites become zero. Besides, the fact that a test shows zero just means that the bacteria have caught up with the die-off, not that the die-off itself has stopped (other wise the nitrates would be lowering also).

 

As I have said before, denitrification is a process that can easily be established with even a small sand bed and the rocks. Also, the denitrifiers are often anaerobes who often can switch between aerobic and anaerobic respiration.

 

i thought denitrifiers were obligate anaerobes? i have never heard of them being facultative anaerobes.

 

is there any reference material that you can point out to about denitrification occurring in small sand beds? there are obviously some parts within the rock where anoxic conditions may prevail and thus denitrification should be able to occur, but i would assume such pockets are too isolated and small to allow for much effective denitrification.

 

in the 20 years that i have maintained home aquaria, i have never seen nitrates lowered solely by the means of denitrification without the addition of a coil denitrators, photosynthetic macroalgae, or deep sand beds. it would be great information if you could point out examples and setups where such reactions have occurred.

[vangvace]

If I were to wager a guess I would say that it was my saying you were still cycling... but that's just my preference for not saying the cycle's over until your near 0 nitrates.

[smedge]

In my mind the "Cycle" is the period where you are building up the bacterial populations that will support the removal of ammonia and nitrite (most people do not use bacterial populations to remove Nitrate, not should they). It's also what the author of "Cycling Your Tank" meant (in the articles section on this site). Nothing is going to happen in the cycle period that will reduce nitrates (I realize this statement is not entirely correct due to the slow buildup of anerobes in anoxic areas). Nitrate removal is independent of the initial tank cycle.

 

It wasn't my intent to tell the OP that they should start stocking SPS cause their cycle was over (thereby killing them with high nitrates). Instead I was getting at the fact that "waiting" any longer for the "cycle to complete" would do nothing to affect Nitrate levels; and it won't. So it was not just semantics. It was me telling them that increasing nitrates are expected and that they must be dealth with actively.

 

The "misinformation" I was referring to was that the OP was asking if they should wait longer for the nitrates to lower, coupled with the fact no one told them "no you should not wait" coupled with a comment or two claiming they were still cycling as evidenced by the high nitrates.

 

Maybe I didn't communicate my point 100%, but I definately have my facts straight. And my tone... Lak you should know by now how easily tone is misinterpreted in boards

[lakshwadeep]

i thought denitrifiers were obligate anaerobes? i have never heard of them being facultative anaerobes.

 

is there any reference material that you can point out to about denitrification occurring in small sand beds? there are obviously some parts within the rock where anoxic conditions may prevail and thus denitrification should be able to occur, but i would assume such pockets are too isolated and small to allow for much effective denitrification.

 

in the 20 years that i have maintained home aquaria, i have never seen nitrates lowered solely by the means of denitrification without the addition of a coil denitrators, photosynthetic macroalgae, or deep sand beds. it would be great information if you could point out examples and setups where such reactions have occurred.

 

Try reading part VI in this article:

http://www.nano-reef.com/articles/?article=17

 

I'm basing my small sand bed comment from a magazine article. I'll try to look up the specific quote. Also, I don't mean to say that nitrates are lowered solely by denitrification because I constantly recommend, and perform myself, weekly water changes. However, I do think that my tank's bioload, one firefish in a 20H, and its age probably help create a more thorough denitrification.

[supraeli]

Try reading part VI in this article:

http://www.nano-reef.com/articles/?article=17

 

I'm basing my small sand bed comment from a magazine article. I'll try to look up the specific quote. Also, I don't mean to say that nitrates are lowered solely by denitrification because I constantly recommend, and perform myself, weekly water changes. However, I do think that my tank's bioload, one firefish in a 20H, and its age probably help create a more thorough denitrification.

 

great read, lak, thanks for the recommendation. however, from what i gleaned from the article, it says that denitrification occurs months after the tank is setup, so that would mean that an equally long period of time would occur before nitrates would fall.

 

i think this is an important point to mention because it appears that you have pushed for the concept that a cycle is not complete until nitrates START to fall, and perhaps even register zero, which would probably take months if not years. this, of course, does not coincide with the concept of a "cycle." after all, we all know that livestock can be added as soon as ammonia and nitrite have reached non-measurable levels while nitrates may still be detectable and removed with traditional water changes.

 

i still consider the concept of denitrification inside our minute bodies of water to be an unknown field and would hesitate to find it accountable for falling or no nitrate levels. even you, lak, have mentioned that you have only one tiny fish in 20 gallons and regular water changes - in this case, i HIGHLY doubt that zero nitrates is the result of denitrification, but instead, the formerly mentioned aspects of your system.

 

either way, thanks for enlightening me by pointing out the article.

[The Propagator]

Cycle time is relative to so many things to narrow it down to time alone is foolish.

 

The amount of rock, is the rock cured? If so how well was it cured? Porous v's non porous rock, crushed coral versus sand or aragonite, bioballs v's rock rubble, skimmed or skimmerless, the amount of actual water volume.. etc etc etc....

 

I set up a 75 gallon tank using a 50/50 mix of new and old substrate and all old rock.

10 days later completely cycled and ready to rock.

I started my 100 up from scratch but with supposedly cured rock from a local LFS.

4 months later it was cycled.

My 29g took 2 months.

My 40's took about 3 weeks each.

 

Its relative to which method you use as well. IE water changes versus no water changes during cycle times.

Fish or no fish to help boost the cycle......

Nitrates can read -0- weeks into the initial set up or it could take months.

 

That fact is all we can do is judge our own systems by what we have going on respectively in our little glass boxes at the time. Because we are the only ones that truly know whats there and whats not.

What worked for me, may or may not work for you.

What worked for Lak may or may not work for me..... etc etc etc....

But so far no one is truly giving missinformation at all. Its all true given a set of variables.

You just have to remember that variables are key here. For ever changing, and non constant form one user to the next.

 

Nitrates reading -0- or .25 is a moot point IMHO.

Why ? The test kits we use are simply not accurate enough ( with out spending $120 or more on a pro Hatch or a pro Lamotte kit that is ). Even what reads -0- is just an exceptionally acceptable reading that falls under what the manufacturer has calibrated their solutions to read -0-.

IMHO if its under 5-10 your golden.

 

You truly can achieve -0- trates though if your using a DIY coil type denitrator or similar though.

But that also requires a constant balance in your inhabitants because every time you up the bio load your upping the amount of bacteria needed to eat the waste.

[bdare]

I would agree that everyone here is right to a point and really just comes down to a matter of personal preference.

 

I will also state that either Calfo or Borneman said that the cycle is not TRUELY over until all the mini-cycles following the initial cycle have ceased and your nitrates have been reduced to ZERO. Under thier reccomendations you should not add any fish or corals until this process has completed around 6 months after the tank was setup.

 

Obviously, as much as we try to take things slow in this hobby we do not follow this line of thinking and thus have come up with our own rules about when we feel it's safe to add inhabitants to our tanks. I also subscribe to the idea that once Amonia and nitrites are nil I add fish, but is this really ideal? IMO this could be debated for a long time and as I stated in the beginning of this post it really just comes down to personal preference.

[HankB]

I would agree that everyone here is right to a point and really just comes down to a matter of personal preference.

 

I will also state that either Calfo or Borneman said that the cycle is not TRUELY over until all the mini-cycles following the initial cycle have ceased and your nitrates have been reduced to ZERO. Under thier reccomendations you should not add any fish or corals until this process has completed around 6 months after the tank was setup.

 

...

 

IMO true but overly conservative.

 

I think it more useful to think of the cycle as establishing a balance between bioload and biological filter. Technically, once ammonia and nitrites reach zero the biofilter is in place to convert ammonia to nitrites and nitrites to nitrates. Denitrification - to whatever extent it does or does not happen in a nano - takes longer to start.

 

My point is that once the NH4/NO2 reach zero the balance remains tenuous. It is less useful to think of this as "done and move on." Stocking should proceed slowly at this point to avoid upsetting the balance. I suspect this would be necessary even if one waited six months to start stocking.

 

The other thing I'll add is that most corals photosynthesize and compete with algae for nitrates and phosphates. This is one reason why algae is difficult to control in a tank with only a few small frags.

 

HTH,

hank

[bdare]

IMO true but overly conservative.

 

I think it more useful to think of the cycle as establishing a balance between bioload and biological filter. Technically, once ammonia and nitrites reach zero the biofilter is in place to convert ammonia to nitrites and nitrites to nitrates. Denitrification - to whatever extent it does or does not happen in a nano - takes longer to start.

 

My point is that once the NH4/NO2 reach zero the balance remains tenuous. It is less useful to think of this as "done and move on." Stocking should proceed slowly at this point to avoid upsetting the balance. I suspect this would be necessary even if one waited six months to start stocking.

 

The other thing I'll add is that most corals photosynthesize and compete with algae for nitrates and phosphates. This is one reason why algae is difficult to control in a tank with only a few small frags.

 

HTH,

hank

 

I totally agree... I was just playing devils advocate

[lakshwadeep]

great read, lak, thanks for the recommendation. however, from what i gleaned from the article, it says that denitrification occurs months after the tank is setup, so that would mean that an equally long period of time would occur before nitrates would fall.

 

i think this is an important point to mention because it appears that you have pushed for the concept that a cycle is not complete until nitrates START to fall, and perhaps even register zero, which would probably take months if not years. this, of course, does not coincide with the concept of a "cycle." after all, we all know that livestock can be added as soon as ammonia and nitrite have reached non-measurable levels while nitrates may still be detectable and removed with traditional water changes.

 

i still consider the concept of denitrification inside our minute bodies of water to be an unknown field and would hesitate to find it accountable for falling or no nitrate levels. even you, lak, have mentioned that you have only one tiny fish in 20 gallons and regular water changes - in this case, i HIGHLY doubt that zero nitrates is the result of denitrification, but instead, the formerly mentioned aspects of your system.

 

either way, thanks for enlightening me by pointing out the article.

 

I'm of the opinion that stocking should be slow, meaning months or weeks for cured rock, and that the nitrates will be thus be low before heavily stocking, which helps avoid nuisance algae blooms. Zero nitrates shouldn't be the objective, but instead less than 10 ppm is an acceptable range, as stated by Prop. Yes, the wait for low nitrates may be months (surely not a year), but it does happen. Denitrification probably plays a role for established tanks of many members to survive without water changes for many weeks. I remember even Chris Marks going with only top offs for at least a month. However, hankb is right that the zooxanthellae and other algae play a large role in reducing nitrates on their own.

 

This article is related to the subject under myth 15 from borneman, who could be considered "overly conservative":

http://www.reefkeeping.com/issues/2004-01/eb/index.php