What could keep Nitrates low, almost undetectable

[SaracensRugby]

So, I have a 1 month old tank but the question applies to my old tank as well from which I brought everything (rock, fish, corals) over.

What could keep nitrates low? If one was not specifically trying to have a ULN tank? My nitrate was about 5 when I moved everything, combining newly cycled rock with my current live rock, but has gone down to zero or close to it over a month. My previous tank where I pulled everything from had nitrate close to zero as well.

I run a refugium and skimmer, and feed a mix of pellets, frozen mysis and Larrys, as well as some Zoplan every other day or so. I have 11 fish in my 127 gallon tank, and am using a Trigger Triton sump, so no filter socks (just letting detritus build in the refugium).

I change about 20% of the water each month (both tanks).

Thoughts? Should I back off the water changes a bit, feed more, add more fish over time, or dose nitrate to get to 3-5ppm?

Cheers.

 

[Rollman]

I’m curious as well. I even took the carbon out of my sump. My nitrates have been 0 for 2 months. Things are growing though, tank has a 1 year bday coming up. I do 5% weekly.

 

[Randy Holmes-Farley Verified Community Expert]

So, I have a 1 month old tank but the question applies to my old tank as well from which I brought everything (rock, fish, corals) over.

What could keep nitrates low? If one was not specifically trying to have a ULN tank? My nitrate was about 5 when I moved everything, combining newly cycled rock with my current live rock, but has gone down to zero or close to it over a month. My previous tank where I pulled everything from had nitrate close to zero as well.

I run a refugium and skimmer, and feed a mix of pellets, frozen mysis and Larrys, as well as some Zoplan every other day or so. I have 11 fish in my 127 gallon tank, and am using a Trigger Triton sump, so no filter socks (just letting detritus build in the refugium).

I change about 20% of the water each month (both tanks).

Thoughts? Should I back off the water changes a bit, feed more, add more fish over time, or dose nitrate to get to 3-5ppm?

Cheers.

What nitrate kit are you using?

If it is actually low and so is phosphate, I’d first feed more/get more fish unless you think you are at capacity, at which point I’d consider dosing.

Backing off on the refugium light cycle hours is another good option, assuming you have macroalgae in it.

The water changes are neither the main issue with nitrate, nor a problem for other reasons, but many people like to experiment with more or less water changes to see the effects.

 

[foxt]

Thoughts? Should I back off the water changes a bit, feed more, add more fish over time, or dose nitrate to get to 3-5ppm?

All of those will raise nitrate, the method of choice depends on what you are trying to promote by raising nitrates. Are you looking for benefits for your coral? You are exporting/consuming more nitrate than is being produced. You didn’t say what you have in the fuge, or how you are running the skimmer, but those will help drive nitrate lower. You have a light bio load and don’t sound like you feed a lot, so that will keep nitrate production down. What is your objective?

 

[Eagle_Steve]

So, I have a 1 month old tank but the question applies to my old tank as well from which I brought everything (rock, fish, corals) over.

What could keep nitrates low? If one was not specifically trying to have a ULN tank? My nitrate was about 5 when I moved everything, combining newly cycled rock with my current live rock, but has gone down to zero or close to it over a month. My previous tank where I pulled everything from had nitrate close to zero as well.

I run a refugium and skimmer, and feed a mix of pellets, frozen mysis and Larrys, as well as some Zoplan every other day or so. I have 11 fish in my 127 gallon tank, and am using a Trigger Triton sump, so no filter socks (just letting detritus build in the refugium).

I change about 20% of the water each month (both tanks).

Thoughts? Should I back off the water changes a bit, feed more, add more fish over time, or dose nitrate to get to 3-5ppm?

Cheers.

I ran into this same issue with my setup. I am running with a somewhat Triton Method, and have been playing with the whole method (long story). I have numerous types of macro algae in my sump, and the growth was ridiculous. Well with the growth being 3 gallons of cheato alone in a month, it was consuming every little bit of everything it could. I am also one of those people that like fat happy fish, so the feeding is probably well more then needed. Long story short, I originally had my fuge lights for about 14 hours run time, on a sort of opposite schedule from my DT. Playing around with this I found that about 7 hours of light get me to hang around 2-5 nitrate wise, and I feed the same as before. My assumption is that with the original schedule for the lights, the growth of the macro algae on the lighting schedule, the macro algae was just eating like a glutton. I am still producing a ton of algae for my goats to munch on, but am down to 2 gallons of cheato, and about a gallon of all the others. My corals have also look a little bit happier keeping it around 2-5. Now being as I do not know your full setup, this might not be the case for you, but figured maybe it would help you identify something that may need to be looked into on your setup/fuge setup.

 

[SaracensRugby]

What nitrate kit are you using?

If it is actually low and so is phosphate, I’d first feed more/get more fish unless you think you are at capacity, at which point I’d consider dosing.

Backing off on the refugium light cycle hours is another good option, assuming you have macroalgae in it.

The water changes are neither the main issue with nitrate, nor a problem for other reasons, but many people like to experiment with more or less water changes to see the effects.

I was using salifert test kits, then recently switched to Red Sea. I used both tests side by side while combing tanks and they gave me the same results.

All of those will raise nitrate, the method of choice depends on what you are trying to promote by raising nitrates. Are you looking for benefits for your coral? You are exporting/consuming more nitrate than is being produced. You didn’t say what you have in the fuge, or how you are running the skimmer, but those will help drive nitrate lower. You have a light bio load and don’t sound like you feed a lot, so that will keep nitrate production down. What is your objective?

I am running my Vertex skimmer 24/7, it isn't pulling a ton out so to speak. I have normal chaeto in my sump, about a gallon and a half I guess. I run the lighting schedule in there opposite my display lights, so fuge lights are on about 12 hours. I am using a 6500 CFL bulb on a string until my H160 gets here in a few days. I want to raise nitrates a bit for coral health. I think I lost some SPS in my old tank, and I know there is a lot that could factor into it, due to nonexistent nitrates. I am just trying to cross things off the list in my new tank as I go. Many things I read seem to say nitrates 3-5 are probably best for coral health.

 

[Eagle_Steve]

I was using salifert test kits, then recently switched to Red Sea. I used both tests side by side while combing tanks and they gave me the same results.



I am running my Vertex skimmer 24/7, it isn't pulling a ton out so to speak. I have normal chaeto in my sump, about a gallon and a half I guess. I run the lighting schedule in there opposite my display lights, so fuge lights are on about 12 hours. I am using a 6500 CFL bulb on a string until my H160 gets here in a few days. I want to raise nitrates a bit for coral health. I think I lost some SPS in my old tank, and I know there is a lot that could factor into it, due to nonexistent nitrates. I am just trying to cross things off the list in my new tank as I go. Many things I read seem to say nitrates 3-5 are probably best for coral health.

In regards to your cheato, is that a gallon and a half of cheato in there? If so, have you been removing some every so often? I try to keep my cheato and other algae down to about the size of a softball. With that being said, I am removing a huge amount of it every week. Leaving a huge amount in there allows for a lot more growth on top of growth, if that makes sense. For example, a softball size amount has "X" room for growth and a volleyball size amount has "Y" room for growth. "Y" would of course be a much large number. Being as I have no idea how to figure out the math for cheato growth, this is just an example, and could be entirely wrong lol. My experience has been if I leave the lights for a long time, let my cheato and other algae take over the sump, nitrates are non-existent. When I cut the lights down, the cheato growth slowed, thus consuming less nutrients. I have always removed excess from my initial start size of the algae, so I have no data on if that helped in my case, but I can say that I am removing a lot less algae now that i turned the lights down. Again this is just a guess as a sump with no algae consumes almost no nutrients, a sump with a small ball of cheato will consume a small amount, and a sump with a ton will consume a lot.

If for some reason I jacked all this up, someone please let me know lol. Don't want to misguide someone on the nutrient export process.

As for the SPS, my experience has been 2-5 range has helped mine out a lot. No nitrates in mine and the growth was slow to almost nothing and the color was not near as vivid. Moving to keeping nitrates in the low range has helped. I have even had better growth out of LPS and softies as well. I do have to say I was worried as I have anemones also, and you always hear 0 is best, but they are brighter and growing better also. Also, the above stated was not changing anything but my lighting schedule on the fuge. I haven't changed light setting in the display or anything else. Just getting my nitrates up a bit made a world of difference in my tank.

 

[foxt]

The other indicator, mentioned by Randy, is phosphates. What level do you have in the tank?

 

[jda]

IMO, the fluctuating numbers in a one month old tank will make an impossible target to hit. Once the tank gets more established, your sand and rock (if not dry/dead and gummed up with junk), will get anoxic zones that will keep nitrate very low. This is hardly a problem. Mine are undetectable on any hobby grade kit and need to be sent out along with IC/ICP to get a reading of about .1 - this is enough for a thriving tank.

I agree with most others that it is about throughput than an actual number. A tank with .1 N can have plenty of building blocks passing by as a tank with larger amounts in the water. If you are not carbon dosing or otherwise artificially lowering your level, then you likely have nothing to worry about. In any case, these are worries 6-12 months from now... and not today.

 

[SaracensRugby]

The other indicator, mentioned by Randy, is phosphates. What level do you have in the tank?

Just checked them with my salifert test, and it looks to be Zero. Never could get phosphates to register in my previous tank either; which I knew to be untrue because I could grow GHA in my refugium and had growth of chaeto.

 

[SaracensRugby]

IMO, the fluctuating numbers in a one month old tank will make an impossible target to hit. Once the tank gets more established, your sand and rock (if not dry/dead and gummed up with junk), will get anoxic zones that will keep nitrate very low. This is hardly a problem. Mine are undetectable on any hobby grade kit and need to be sent out along with IC/ICP to get a reading of about .1 - this is enough for a thriving tank.

I agree with most others that it is about throughput than an actual number. A tank with .1 N can have plenty of building blocks passing by as a tank with larger amounts in the water. If you are not carbon dosing or otherwise artificially lowering your level, then you likely have nothing to worry about. In any case, these are worries 6-12 months from now... and not today.

Thanks for the insight. I am trying to get a head of the curve so to speak, as this happened in my previous tank and at 2.5 years in this hobby I finally feel like I am moving past the complete noob stage and am trying to grasp more difficult chemistry/overall big picture topics of these little pieces of ocean. And by moving past the noob stage I partly mean not making knee jerk changes to my system after reading one thing, ending up overcorrecting the "problem" in the process.

 

[jda]

The best thing that you can do for your tank long term is to keep up on water changes even if your "parameters" might say otherwise.

The best example of why is phosphate binding to aragonite. I did an experiment and although the rate of binding increases as the water level increases, the rock and sand can hold about 350x what is found in the water. ...so while .05 P does not sound like a lot in the water, there is a lot in the rock and sand. ...so getting 20%, or whatever, of this out over time keeps things from getting crazy later.

Also, do not use any GFO, organic carbon, LC, etc. without a very good reason and a very precise way to measure it. The bacteria in the tank can handle the nitrate, water changes and fuge can handle the phosphate all with a good dose of patience.

 

[Randy Holmes-Farley Verified Community Expert]

Just checked them with my salifert test, and it looks to be Zero. .

Then feeding more or more fish plus more food is a good plan.

 

[SaracensRugby]

Thanks for all of the info. Question though: some say that our hobby tests can have trouble reading lower levels of phosphate and nitrate, yet some other people with said hobby test kits get readings from them in low/medium/high levels. Why do some get readings and some not? Just trying to understand why there may be differences from one person to another.

Thanks!

 

[foxt]

Then feeding more or more fish plus more food is a good plan.

I agree, this is a better approach longer term vs, dosing nitrate. Plus it means that you can add more fish!

 

[jda]

You can get pretty good low range test results with a Hannah Ultra Low Phosphorous checker - you can read from 0 to .003 with it. Nitrate is a different story unless something has come out recently that I have no idea about.

 

[foxt]

Thanks for all of the info. Question though: some say that our hobby tests can have trouble reading lower levels of phosphate and nitrate, yet some other people with said hobby test kits get readings from them in low/medium/high levels. Why do some get readings and some not? Just trying to understand why there may be differences from one person to another.

Thanks!

I find the color-based kits to be very subjective between individuals, and have had great results on phosphates with the Hanna ulr phosphate checker for example. For nitrate, do you use the version of salifert where you look top down at the vial, or through the side?

 

[Randy Holmes-Farley Verified Community Expert]

Thanks for all of the info. Question though: some say that our hobby tests can have trouble reading lower levels of phosphate and nitrate, yet some other people with said hobby test kits get readings from them in low/medium/high levels. Why do some get readings and some not? Just trying to understand why there may be differences from one person to another.

Thanks!

Different kits have greatly different accuracy and lowest levels of detection, some people have different ideas of what is low and high, and some people assume kits are accurate without actually testing to see if see if they are accurate or not.