Help!!! KNO3 solution

[Fr4nkthet4nk]

Hello reefers,

I am unable to measure any Nitrate in my tank. I am concerned because I am starving my corals.

I am trying to find out how to create a solution of KNO3 using Greenleaf KNO3. I have not been able to find how to make it. Please, can someone let me know how to make it?
Thank you!

 

[jda]

There are many threads on this. The short story is that you are not starving your corals if you are not artificially lowering nitrate with organic carbon or some other chemical or media. If you are NOT doing this and you have fish that you feed, then everything gets fed in a equilibrium and there is nothing left over for your test kit to measure. Chaeto, rock, sand and a skimmer cannot take you too low on their own.

We do not have access to good test kits for Nitrate, but you probably have some.

Depending on how your tank is set up, and how mature it is, dosing nitrate might not help at all. If I dosed nitrate in my tank, all that it would do is cause a surge in anoxic bacteria that would quickly take the nitrate back down to zero. Mature tanks with sand, effective live rock, etc. can keep N low quite effectively, but they always leave some to drive the equilibrium... so you are not starving your corals. Chaeto is the same way... it will keep it low, but not too low.

If you are dosing organic carbon, media or chemicals, then I would always make sure that you have a trace of N since these can take levels too low and make corals very fragile.

Low Nitrate starving corals is a distraction and red herring to most reefers. It can be real for some, but it is so detail dependent, I would not recommend starting this until you understand all of these details of your system and what they are doing. In order to get any real help, a comprehensive list of your tank is probably a good idea.

 

[Reef Jeff]

There is a nice calculator on this website. http://www.theplantedtank.co.uk/calculator.htm

Select the option for Nitrate from Potassium Nitrate and plug in the numbers and units of measure you prefer. JDA makes some good cautions to you. I don't fully agree with allowing ultra low levels of NO3 as I do see improvement in my coral colors polyp extension and growth when I have levels that are detectable by a test kit like Red Sea Algae pro. I maintain NO3 at 1-2 ppm, usually closer to 1 ppm. I use Sodium Nitrate. If my potassium goes down a little, I use Potassium Nitrate till its is back at 400 and then switch back to Sodium Nitrate. I dose very small amounts. I have never seen the need to go higher than 2 ppm. I also find that below a .25 ppm NO3 on the Red Sea kit causes paling and slower growth. If you decide to dose, do it small and monitor nitrates and phosphates.

Also remember, dosing should not be used as a replacement for coral foods. Feeding corals results in better color, growth and polyp extension, and it helps raise NO3 and PO4 depending on your bioload. NO3 nd PO4 are only part of the equation. Corals don't need detectable levels of these in the ocean...by detectable I mean it is still there but our kits would not be likely to pick up a reading.

Moderation in everything...and go slow and observe.

 

[Fr4nkthet4nk]

I stopped dosing NOPOX like 2 months ago because I lowered my nitrates from 40 ppm to 10 ppm. I notice that my Nitrates keeps going down but now they are undetectable and Phosphate is at 0.01ppm.
My tank is around 130 gallon. I have a sump that has a lot of macroalgae right now and some corals are losing color.

 

[Fr4nkthet4nk]

There is a nice calculator on this website. http://www.theplantedtank.co.uk/calculator.htm

Select the option for Nitrate from Potassium Nitrate and plug in the numbers and units of measure you prefer. JDA makes some good cautions to you. I don't fully agree with allowing ultra low levels of NO3 as I do see improvement in my coral colors polyp extension and growth when I have levels that are detectable by a test kit like Red Sea Algae pro. I maintain NO3 at 1-2 ppm, usually closer to 1 ppm. I use Sodium Nitrate. If my potassium goes down a little, I use Potassium Nitrate till its is back at 400 and then switch back to Sodium Nitrate. I dose very small amounts. I have never seen the need to go higher than 2 ppm. I also find that below a .25 ppm NO3 on the Red Sea kit causes paling and slower growth. If you decide to dose, do it small and monitor nitrates and phosphates.

Also remember, dosing should not be used as a replacement for coral foods. Feeding corals results in better color, growth and polyp extension, and it helps raise NO3 and PO4 depending on your bioload. NO3 nd PO4 are only part of the equation. Corals don't need detectable levels of these in the ocean...by detectable I mean it is still there but our kits would not be likely to pick up a reading.

Moderation in everything...and go slow and observe.

How often should I feed my corals? I am doing it once a week using reefroid. I have notice some lack of color in some sps

 

[Reef Jeff]

I had the same experience. NOPOX works great and it kindled the anerobic bacteria in my tank. I no longer need NOPOX. My system now consumes Nitrates and Phosphates at a level that requires very infrequent dosing. I use no nitrate removing compounds, no GFO, no carbon dosing, no refugium, just GAC and a skimmer. I do have a lot of live rock (20+ years old now).

 

[jda]

I run my tank a undetectable N (it is .1 on IC analysis, but I cannot do this at home). P is .01. Everything is colorful and fine. Throughput is what you are after. Do you have a good fish load? If so, then keep feeding them and they corals will get fed. There is nothing that I could do to get my N up, even if I wanted to. The tank would just adjust and process it down again.

I would look to constantly changing parameters with SPS color loss. ...or lighting.. corals with lots of zoox are easy to light.

Some SPS will look different with less N and P, but some like them better this way. Lower N and P usually has brighter colors with more contrast at my house. Higher N and P will have richer, deeper colors, but less bright and less contrast. To each their own. If your colors were deeper/darker and you miss this, then take a bunch of the algae out and see if it helps... dosing N and having algae is counterproductive. Give the system some time - if you have good full-spectrum (not LED full spectrum, but actual full spectrum) lighting, then in a few months, you might really like how the color up. You might also miss the richer/darker look. I dunno.

If stuff was RTNing or dying, then it might be a sign of truly too-low nitrates.

Lastly, and sorry, it can take a year, or more, for enough anoxic zones to establish to chew up nitrates and turn them into N gas. For some people, they use a product when time is all that they needed. If this magic happened in the 9 to 18 month mark, then it was probably just nature and maturity more than any product.

 

[Reef Jeff]

I feed reefroids, oyster feast and phytofeed every 2-3 days and I target feed. Corals respond well to this. All of these raise phosphate, so monitor phosphate levels as well.

 

[hatfielj]

It is possible to have too low of nutrient levels with just skimming and especially with a fuge running. I think we have mentioned to you in a previous thread that you should consider getting rid of your macroalgae. That is likely what is causing your undetectable levels and causing your corals to lose color. I've had the same thing happen in previous tanks. That's a far easier solution than dosing nitrates/phosphates.

However, if you prefer to dose KNO3, Randy Holmes-Farley has recommended a solution of 10 grams KNO3 per 1000 mL of RO water. That is the concentration I use. For your tank, using the calculator provided above, if you dose 1 mL of the 10 g/1000mL solution, you should raise your nitrate by 0.01ppm. If I were you I would start with adding maybe 25-50 mL per day and see if you can get a detectable level. 50 mL should raise your nitrate by about 0.5 or so PPM (according to the calculator). Go slow or you will set off an algae bloom. It took me several weeks of dosing to get up to the 5 ppm range I wanted. Most likely what will happen with your tank once you start dosing is your macro algae will consume it all before you will see a detectable level. Your fuge will go bonkers with algae growth before you see any rise in your tank's levels. You'll probably see darker green color in your macro algae instantly. You will also see your Phosphate level become undetectable as well after you start dosing so you might need to start dosing that as well. Again, the easier solution now is to remove your macro algae completely

 

[Fr4nkthet4nk]

It is possible to have too low of nutrient levels with just skimming and especially with a fuge running. I think we have mentioned to you in a previous thread that you should consider getting rid of your macroalgae. That is likely what is causing your undetectable levels and causing your corals to lose color. I've had the same thing happen in previous tanks. That's a far easier solution than dosing nitrates/phosphates.

However, if you prefer to dose KNO3, Randy Holmes-Farley has recommended a solution of 10 grams KNO3 per 1000 mL of RO water. That is the concentration I use. For your tank, using the calculator provided above, if you dose 1 mL of the 10 g/1000mL solution, you should raise your nitrate by 0.01ppm. If I were you I would start with adding maybe 25-50 mL per day and see if you can get a detectable level. 50 mL should raise your nitrate by about 0.5 or so PPM (according to the calculator). Go slow or you will set off an algae bloom. It took me several weeks of dosing to get up to the 5 ppm range I wanted. Most likely what will happen with your tank once you start dosing is your macro algae will consume it all before you will see a detectable level. Your fuge will go bonkers with algae growth before you see any rise in your tank's levels. You'll probably see darker green color in your macro algae instantly. You will also see your Phosphate level become undetectable as well after you start dosing so you might need to start dosing that as well. Again, the easier solution now is to remove your macro algae completely

Yes. I removed half of my algae but I haven't seen a change. I will remove half of the half to see what will happen before dosing KNO3. Thank you!

 

[jda]

Also remember, dosing should not be used as a replacement for coral foods. Feeding corals results in better color, growth and polyp extension, and it helps raise NO3 and PO4 depending on your bioload. NO3 nd PO4 are only part of the equation. Corals don't need detectable levels of these in the ocean...by detectable I mean it is still there but our kits would not be likely to pick up a reading.

NWS in the coral sea is about .1 nitrate and .005 phosphate. The collectors that we saw there supplement their NSW when they pump it into holding tanks with zooplankton - there is not enough on the reef for the corals to eat in nature, but they get all of the light that they want for food. ...so .1N, .005P and sunlight are what grows the colonies there. Other places are different where more food is around and corals can filter feed. They were highly skeptical that acros filter feed as much as people think and one fella thought that people were confusing atoll lagoons (more nutrient rich) with the open water.

I all that I know is that I can feed my coral (acropora only), or not, and nothing changes... but I do have massive amount of Halides over them for food. I know that people swear by coral feeding, so there is something else at work here, but I do not think that it balances N and P lowness, but light. There is something there between building blocks (N&P) and true food the the zoox provides - I am not smart enough to know this. Some have supposed that in tanks with higher levels of N and P, that it is the higher levels urea and ammonium that feed the corals, not the N and P. Again, I dunno.

BTW - 1 ppm of nitrate on Red Sea is undetectable on Salifert. You and I could have the exact same amount for all that we know. When I sent in water to IC test, it came back .1 and red sea said that it was just under 1ppm (you know how hard they can be to read).

 

[xiaoxiy]

I all that I know is that I can feed my coral (acropora only), or not, and nothing changes... but I do have massive amount of Halides over them for food. I know that people swear by coral feeding, so there is something else at work here, but I do not think that it balances N and P lowness, but light. There is something there between building blocks (N&P) and true food the the zoox provides - I am not smart enough to know this. Some have supposed that in tanks with higher levels of N and P, that it is the higher levels urea and ammonium that feed the corals, not the N and P. Again, I dunno).

Here's a excerpt taken out of the Coral Husbandry section of Marine Ornamental Species Aquaculture (Calado et. al 2017)

It has been demonstrated that heterotrophic feeding increases photosynthetic rates of the symbionts, which could also mean that more photosynthetic products are available to the animal host (Houlbrèque & Ferrier‐Pagès, 2009). Corals fed with live prey also have twofold greater organic matrix synthesis, calcification, protein and lipid content than starved corals (reviewed by Houlbrèque & Ferrier‐Pagès, 2009). Moreover, skeletal growth can be 30% higher in fed corals, as verified for the symbiotic corals Stylophora pistillata and Turbinaria reniformis (Ferrier‐Pagès et al., 2003; Treignier et al., 2009). Heterotrophic feeding also improves coral quality as it contributes to maximize resil- ience to stress and potential for recovery (Grottoli et al., 2006). This is important to increase the tolerance of corals to changes in water quality and light variation that often occur in the MOT.

I remember reading a paper about the effect of PAR and coral feedings, in which the authors regularly fed corals under ~100 vs 300PAR. The findings showed that feedings at ~100 PAR didn't seem to make a difference in growth rates, but feedings at ~300PAR increased growth rates. I'll have to dig the paper up and post the source.

Here's the same author's take on inorganic nitrogen

Nitrogen is usually a limiting nutrient in oligotrophic coral reef environments (concentrations <0.5 μM, (Atkinson et al., 1995)). It is mainly found as nitrate, ammonia and urea, and is needed for growth. Both internal and external nitrogen sources are available to corals. Indeed, urea and ammonia, two forms of nitrogen that are by‐ products of coral host metabolism, are not excreted and released by the symbiotic association, but are re‐used by the symbionts and transformed into photosynthates (Muscatine & D’Elia, 1978). The uptake of seawater inorganic nitrogen is also mediated by the symbionts, although the coral host has adapted to transport these molecules through its membranes (Grover et al., 2002; Godinot et al., 2009). The availability of nitrate (NO3–) and ammonia (NH4+), which are the two main forms of seawater inor- ganic nitrogen, is critical for coral growth and particularly important during heat‐stress (Godinot et al., 2011a). The latter study further showed that the stony coral Stylophora pistillata decreases its capacity to take up nitrogen under such conditions. However, this same coral species is able to maintain its photosynthetic capacity if nitrogen is sup- plied (Béraud et al., 2013). Thus, nutrient enrichment can maximize coral quality and quantity (Godinot et al., 2011b). In contrast to the supply of live prey, where the acquired nutrients are first available to the coral host, the artificial supply of inorganic nutrients primarily affects the symbionts hosted in the coral tissue. This occurs through an increase of protein, lipid and chlorophyll concentration in symbiont cells and by stimu- lating proliferation of the symbionts (reviewed by Houlbrèque & Ferrier‐Pagès, 2009). Nevertheless, nitrogen assimilated by the symbionts is rapidly translocated to the coral host (Piniak & Lipschultz, 2004). Nitrogen enrichment only works up to a certain level, above which eutrophication problems (chaotic development of bacteria, phytoplankton and algae) may affect the culture system. In addition, although most corals readily use inorganic nitrogen, both ammonia and nitrate are highly toxic to most marine life and can damage sensitive animal tissues at high concentrations (Muller‐Parker et al., 1994; Grover et al., 2003).

My take away is that to a certain extent, feeding and inorganic nutrients can significantly enhance photosynthesis and growth rates in the corals we take. However, it is a fine balance because too many nutrients, however, can lead to a nasty tank.

 

[Makomek]

IMO dosing NO3 is your last resort if any other method doesn't work. Feeding more and skim less/off with fewer WC Is the first thing you should do and wait a month or two, pale corals won't die so be patient. Dosing NO3 will bring in some nasty algae and cyano and can go out of hand pretty quick.

 

[Reef Jeff]

NWS in the coral sea is about .1 nitrate and .005 phosphate. The collectors that we saw there supplement their NSW when they pump it into holding tanks with zooplankton - there is not enough on the reef for the corals to eat in nature, but they get all of the light that they want for food. ...so .1N, .005P and sunlight are what grows the colonies there. Other places are different where more food is around and corals can filter feed. They were highly skeptical that acros filter feed as much as people think and one fella thought that people were confusing atoll lagoons (more nutrient rich) with the open water.

I all that I know is that I can feed my coral (acropora only), or not, and nothing changes... but I do have massive amount of Halides over them for food. I know that people swear by coral feeding, so there is something else at work here, but I do not think that it balances N and P lowness, but light. There is something there between building blocks (N&P) and true food the the zoox provides - I am not smart enough to know this. Some have supposed that in tanks with higher levels of N and P, that it is the higher levels urea and ammonium that feed the corals, not the N and P. Again, I dunno.

BTW - 1 ppm of nitrate on Red Sea is undetectable on Salifert. You and I could have the exact same amount for all that we know. When I sent in water to IC test, it came back .1 and red sea said that it was just under 1ppm (you know how hard they can be to read).

Good info here. I run metal halides as well, but could use more intensity (250w each to 400w each). I also supplement with T5's and a DIY LED setup to span entire top of 6' tank. Higher wattage MH could very well make the difference. I hear that lower N/P nutrients cause slight reduction in zooxanthellae which allows the coral's natural pigments to color up which can result in a color change to the coral. Perhaps that is what you are seeing with the lower nutrients when you talk about color vs brightness vs contrast? I have seen similar changes is some different acros in my tank which had a green florescence to them in the LFS's high N/P water under mostly blue LED's and when I got them home in my system after a few months they changed to less green and more of the yellows, blues and purples. I always assumed it was caused by lower N/P, feeding of the corals and higher full spectrum lighting. The brighter more vivid colors with the higher nutrients seem to tend toward the more common algae colors (green, red, brown). What I could never explain was the paling if I let the levels drop much below .25 ppm NO3 and much less than .02 ppm PO4 when the feeding and lighting had not changed. As soon as I dosed within a few days the colors were back as before. This has been repeatable many times with a variety of hard corals. I dunno either, but good info in your post to consider some experiments.

As for the Red Sea kits, they definitely read higher than ICP. Always hard to really know where you are at with hobby test kits, which is one of the reasons I always targeted levels like 1-2 ppm NO3 and detectible PO4 levels.

 

[jda]

I think that it fine to look to nature for your husbandry guide, knowing full well that we are not capable of all of it and that we need to adjust. While I have no doubt that "corals" can benefit from feeding and even some kinds of lagunal SPS like poci and stylos, I have seen absolutely no evidence that acropora get any benefit from feeding on the reef. They thrive with barely detectable building block nutrients and all of the food that they could want from the sun. I am speaking acropora only here... that is what I care about and that was what I focus on. Half of my acros barely have a polyp per inch... others are quite hairy.

While I usually see no harm in feeding corals, even if they cannot eat the food, the reasons why most people feed most stonies is based on some studies from other "corals" with the nuance either missed or left out. A stylo has totally different care than an acropora.

Depending on the SPS, a lack of color is usually light related. Nobody wants to hear that their lights are inferior or not powerful enough, but that is the reality most of the time - better quality and higher output usually yields results that people want. The only real exception to this is that if Montis, Stylos, Birdsnest and Poci have bad color, then it could also be water quality since they can survive and not RTN like an acro would.

Sure, you can pale out if you have higher N and P levels and then they dropped down to NSW. If you wait a few months, they will color up like you see in a lot of other tanks. I will have to see if I can get a good picture, but some of the deepwaters encapsulate this very well... under higher N and P tanks, the stalks are green with colorful tips... think Loripes or Granulosa. With NSW parameters, the stalks are white, not green. Some like the green and some like the white... to each their own.

You decide which one that you like best but the left is NSW parameters and the right is N 0f 5 and P of .10:


@xiaoxiy - I would love to see that paper if you can find it. I am not discounting the study or info, but I really want to find one that shows what kind of corals I keep instead of on some plate corals or porites... this is a big stretch to imagine that they would scale to acropora in a different part of the ocean and with totally different care requirements.

 

[Reef Jeff]

The above pictures are very helpful. Thanks for posting. The NSW shot has very nice purple coloration and nice contrasts, but if that had been in my tank I would have reacted by thinking I had a nutrient and light issue due to the lack of color on the stalk. If I had these side by side in my tank, I would prefer the one on the right. BUT, that is more fear based than anything. I interpret the one on the right as being healthier...not saying that is right, just saying that would be my interpretation based on the little experience I have with Acros.

Like I said, I have seen more green, red and brown in Acros kept in higher nutrient water (as shown on the right). As long as I was getting the tip coloration and contrast like you see in the right picture, I would be very happy with that. There appears to be a bit more blue light on the left shot compared to the right which also affects the tip coloration. I have also seen Acros kept in high level nutrient water where the tips turned green as well. I would not be happy with that, which is why I shoot for 1-2 ppm. You have peaked my interest though. I think your approach with the lower nutrients is worth trying out. Obviously you have been successful otherwise you wouldn't be trying to sell that approach.

 

[jda]

The lights are different, but the white vs. green base/stalks is real. Neither is more healthy than the other. The color differences are personal. People start adding nitrate without understanding or having basis for comparison as to what they are looking for. If somebody like one more than another, then cool... but this is a preference thing and not a crisis.

BTW - I am NOT unto ULNS... it is awesome if you can do it, but I do not have the time. I am just for low, not ultra low. Low is what the tank can do on it's own with bacteria, growth and a fuge since it always leaves enough for the coral. Ultra-low takes media, organic carbon, chemicals, etc.

BTW - count the polyps on these acros... the don't catch much food.

 

[xiaoxiy]

@xiaoxiy - I would love to see that paper if you can find it. I am not discounting the study or info, but I really want to find one that shows what kind of corals I keep instead of on some plate corals or porites... this is a big stretch to imagine that they would scale to acropora in a different part of the ocean and with totally different care requirements.

Found it! The study was performed on Stylophora pistillata.
The Biology and Economics of Coral Growth: Figure 5

 

[jda]

I really love these studies, but why cannot somebody do something on something that I keep. I give Dana a lot of trouble for studying Priotes when I would gladly send him 3-4 dozen frags of acropora for him to study with.

 

[xiaoxiy]

I really love these studies, but why cannot somebody do something on something that I keep. I give Dana a lot of trouble for studying Priotes when I would gladly send him 3-4 dozen frags of acropora for him to study with.

That's what I also cry about every time I do a literature search . No one does these feed studies with acropora. One of the few papers I could find was a study on elevated phosphates increasing calcification rates in staghorn acropora.