Dosing Potassium Nitrate

[CastAway]

Hmmm. I like this dialog.

The comment about CO2 strikes me in particular. My wife and I continually spar over the Windows these days. I see and measure a direct correlation between outside air flowing through the house (which happens to be cool to my wife's distain) and no outside air, and the effect on my pH. When I've mentioned pH with respect to cyano however, there's been no supporting response.

No harm in letting some time go by. Thanks for all the feedback!

 

[cee]

I seek simple answers as they have the highest probability of being correct. CO2 plays a very important role that is often dismissed. CO2 and its impact on pH is a well-documented phenomenon.

Dave

 

[BlueDevil]

I too have enjoyed this discussion! Thank you everyone! This is great information to keep in my back pocket if I ever have to deal with cyano which I'm sure at some point I will.

 

[CastAway]

Just curious, I don't believe I saw a nitrate level or phosphate level posted by the OP. One of the many things to be cautious with is to carefully know your nitrate and phosphate levels both before and during nitrate dosing. Also other things to consider is your bio load, the type of fish food, feeding amounts, filtration, lighting, flow, GAC, skimming, , carbon dosing or not, gfo or not, on and on. Not trying to make it sound more complicated than it needs to be but don't want to oversimplify either.

Sorry I missed this.
Current measurements:
Sg: 1.026
pH: 8.2
dKH: 9.1
Ca: 460
Mg: 1360
NO3: 0
PO4: 0

210g in volume; I skim 24/7, run a Ca reactor, GFO reactor (10tbls Pura Phoslock), 25g caulerpa laden fuge, 6" DSB, I have a light bio load, and probably feed too heavily (either two cubes of mysis per day, or, one cube of mysis and an equal amount of LRS Reef Frenzy. I've recently quit 6ml of vodka per day, have quit 50ml of Aquavitro Fuel every third day. Lighting is two LED fixtures, each with 78 lenses at 187 watts.

I have some cyano I'm dealing with, but, want to bring my nitrates up at the same time, if possible. Thus the idea of dosing KNO3.

Hope this helps @watchguy123.

 

[BlueDevil]

All your parameters are spot on! So it doesn't appear that NO3 or PO4 are the cause for your cyano.

 

[CastAway]

Well, that part confuses me, because I know that even though I can't measure them, they're there - sync'd I guess. Through other threads I'm gleenjng that's it's best to have measurable NO3, which is what I'd like to achieve. Thus the idea of dosing the KNO3.

If I could get to s point where I could measure 2ppm consistently, and my algae and cyano didn't get worse, I could see some benefit in my SPS, I think. [emoji15]

Making it even more confusing, I think I'm hearing the increasing my NO3 may help may system to deal more effectively with PO4 .

 

[BlueDevil]

Just curious - will there a point where dosing KNO3 will result in nitrates that your macro won't be able to keep up with? Or will the macro will be able to handle it all and go nuts leaving your tank with little to no nitrates even after dosing?

 

[CastAway]

Just curious - will there a point where dosing KNO3 will result in nitrates that your macro won't be able to keep up with? Or will the macro will be able to handle it all and go nuts leaving your tank with little to no nitrates even after dosing?

I suspect the both macro AND SPS will handle it, and the macro, by design, can be harvested to make room for more.

This is what I'm trying to understand, does one simply dose enough NO3 to stay measurably ahead of consumption?

 

[Vaughn17]

I just started dosing nitrate six days ago in my 40g and 38 g tanks. The first four days I dosed a Seachem product called Flourish Nitrogen, which is potassium nitrate and urea. I dosed the recommended dosage of 2.5 ml/40 gallons (which is actually for freshwater tanks). My sps seemed okay with it, and my lps loved it with the exception of four corals: a turbinaria and two green lepto (one in each tank) that bleached moderately, and a chalice that looked unhappy. Ironically, another turbinaria and three different colored leptos were fine. A tiny amount of cynano in both tanks showed no change. Snotty brown dinos in the 38 g tank have almost completely died. The tank wasn't overgrown with dinos, but there was enough to be PIA and now they appear to be on their way out. Seems like an imbalance of nitrate and phosphate may cause problems, but that is just a guess on my part.

Yesterday, I bought some Spectricide stump killer, which is reputedly 100 percent potassium nitrate, as I was thinking my corals that bleached and looked unhappy might have been reacting to the urea in Flourish Nitrogen. After mixing 2 tb per two cups freshwater, I removed a few bristleworms and an ugly montipora frag from my QT, put them in about a cup of tank water, and added 0.05 ml of the nitrogen/water mix. An hour later everything was still alive and kicking, so I dosed my 38 gallon tank with 1 ml last night and 2 ml this morning. This morning, I tested nitrates using a salifert kit. They were still unreadible (not even a hint of pink). I'll test again tonight.

 

[CastAway]

Keep us updated @Vaughn17!

 

[CastAway]

So, with some trepidation, and against the advice of some reefers I respect very much, I started dosing KNO3.

I’m about a week in, and thought I’d share the experience so far.

First, my rationale and goal in trying this:
The consensus I hear, and from people who seems to have thriving SPS, is that coral benefits from detectable nitrate anywhere from .5ppm to 10ppm – sometimes even more. In two years I have only detected nitrates twice, and one was while cycling initially. My guess is that I simply have a lot of export in my system, and that my tank was or is “nitrate limited”. I think this means that I have more potential uptake than my tank can produce, and thus it’s not detectable. I think that the things that take up NO3 more effectively, like algae, out compete my SPS for it. Thus, this may be why I don't see the growth or color I want.

Dosing KNO3 seemed to me like a logical way to raise NO3 levels without having to generate ammonia or nitrites, not to mention introduce phosphates that accompany increased feeding. I was advised by some who seem to have seen some success from dosing KNO3, not to remove any of the existing nutrient export mechanisms, like my DSB and Macro algae laden refugium - so I did not.

So, I made a batch of solution that includes two (2) tablespoons of Spectracide Stump Remover, purportedly pure potassium phosphate (KNO3), and two (2) cups of RODI water.

The evening of Jan 8th, after measuring a baseline NO3 of 0.0ppm, I dosed an initial 25ml of the KNO3 solution. This was based on @twilliard's recommendation and his initial dose of 10ml for his 80g system. An hour later I measured .5ppm NO3, and then, conservatively, I dosed another 10ml. An hour later I tested NO3 at 1ppm. My goal was no greater than 2.0ppm.

The evening of Jan 9th I tested NO3 at <.5ppm, and dosed another 25ml KNO3. An hour later I measured NO3 at <1.5ppm.

The evening of Jan 10th I did not test nor dose.

Today, Jan 11th, I tested NO3 at 1.0ppm, and have decided to remain at this level until I can discern a weekly maintenance dose – I’m expecting no greater than 10ml.

Although my cyano is still present, I do not attribute any increase or worsening to the KNO3, and plan on using Chemi-Clean or Cyano-Clean in the near future.

I may be noticing some change with the increase in NO3. Like @Mark75 noted, I have definitely noticed a lack of film on my glass. I have not had to clean the glass since I started. I attribute this to more effective uptake of phosphate by algae already in my tank. I measured 0.0ppm PO4 on Jan 11th.

I think I may also be seeing a slight difference in coloring and PE. My birds nest seem more vibrant, and, the flesh beneath the polyps is darker. It’s looking the healthiest I’ve seen it. Unfortunately, it’s one of the colonies I care the least about. I also think my zoas and LPS may be more full and brighter.

I am waiting on any noticeable change in my other SPS, and will continue to update, good, bad and ugly.

Questions so far include:
Q: What is the relationship, and what are the risks, with nitrates and dKH?
Q: Using a Red Sea Pro NO3 test, my sample continues to darken after the 9mins. Is this normal?

 

[twilliard]

So, with some trepidation, and against the advice of some reefers I respect very much, I started dosing KNO3.

I’m about a week in, and thought I’d share the experience so far.

First, my rationale and goal in trying this...
The consensus I hear, and from people who seems to have thriving SPS, is that coral benefits from detectable nitrate anywhere from .5ppm to 10ppm – sometimes even more. In two years I have only measured nitrates twice, and one was while cycling initially. My guess is that I simply have a lot of export in my system, and that my tank was or is “nitrate limited”. I think that means that I have more potential uptake than my tank can produce, and thus it’s not detectable. I think that the things that take up NO3 more effectively, like algae, out compete my SPS for it. Thus, this may be why I don't see the growth or color I want.

Dosing KNO3 seemed to me like a logical way to raise NO3 levels without having to generate ammonia or nitrites, not to mention introduce phosphates that accompany increased feeding. I was advised by some who seem to have seen some success from dosing KNO3, not to remove any of the existing nutrient export mechanisms, like my DSB and Macro laden refugium; so I did not.

So, I made a batch of solution that includes two (2) tablespoons of Spectracide Stump Remover, purportedly pure potassium phosphate (KNO3), and two (2) cups of RODI water.

The evening of Jan 8th, after measuring a baseline NO3 of 0.0ppm, I dosed an initial 25ml of the KNO3 solution. This was based on @twilliard's recommendation and his initial dose of 10ml for his 80g system. An hour later I measured .5ppm NO3, and then, conservatively, I dosed another 10ml. An hour later I tested NO3 at 1ppm. My goal was no greater than 2.0ppm.

The evening of Jan 9th I tested NO3 at <.5ppm, and dosed another 25ml KNO3. An hour later I measured NO3 at <1.5ppm.

The evening of Jan 10th I did not test nor dose.

Today, Jan 11th, I tested NO3 at 1.0ppm, and have decided to remain at this level until I can discern a weekly maintenance dose – I’m expecting no greater than 10ml.

Although my cyano is still present, I do not attribute any increase or worsening to the KNO3, and plan on using Chemi-Clean or Cyano-Clean in the near future.

I may be noticing some change with the increase in NO3. Like @Mark75 noted, I have definitely noticed a lack of film on my glass. I have not had to clean the glass since I started. I attribute this to more effective uptake of phosphate by algae already in my tank. I measured 0.0ppm PO4 on Jan 11th.

I think I may also be seeing a slight difference in coloring and PE. My birds nest seem more vibrant, and, the flesh beneath the polyps is darker. It’s looking the healthiest I’ve seen it. Unfortunately, it’s one of the colonies I care the least about. I also think my zoas and LPS may be more full and brighter.

I am waiting on any noticeable change in my other SPS, and will continue to update, good, bad and ugly.

Right on Jeff!!
Keep it up

 

[Mark75]

I am excited to follow your results Jeff! You have a much better test subject since your tank is more established and "grown out", I have trouble decided it changes are due to the dosing or my new tank maturing.

Something I noticed that does not get mentioned, is increasing you lighting or moving corals up as they darken. I am not sure what lighting you are running or if you have the option of increasing? I was running my lights at 70% and noticed some of my lower level SPS where getting darker in color but not brighter, I have increased my lighting to 80% but have not noticed any change yet.

Make sure you test BEFORE dosing every time! Your tank will become saturated and a little will really raise your nitrates a lot.

Good luck

 

[CastAway]

I am excited to follow your results Jeff! You have a much better test subject since your tank is more established and "grown out", I have trouble decided it changes are due to the dosing or my new tank maturing.

Something I noticed that does not get mentioned, is increasing you lighting or moving corals up as they darken. I am not sure what lighting you are running or if you have the option of increasing? I was running my lights at 70% and noticed some of my lower level SPS where getting darker in color but not brighter, I have increased my lighting to 80% but have not noticed any change yet.

Make sure you test BEFORE dosing every time! Your tank will become saturated and a little will really raise your nitrates a lot.

Good luck

Yes, definitely testing, and frequently, especially prior to any KNO3 dose.
My LED's are peaking at 100% on all channels for several hours a day. Short of lowering them, I don't have much of a way to compensate, should I need to. Am watching like a hawk. Not planning any increase however, due to the cyano.

 

[Mark75]

I noticed no difference in dKH.

 

[Vaughn17]

Here is an overview and update regarding the dosing of potassium nitrate in my 38 gallon primarily sps tank. I few months ago some of my acros, which had been growing well and colored up nicely (upon the change to a dimmable T5 fixture), started to stn. The tank has three small fish: a clown, a yellowtail damsel, and a splendid dottyback, no skimmer, and an HOB filter. I dose two part, mag, strontium, and Acro Power. Because acros were browning and I had unknownly neglected to do the required 50 hour bulb burn-in on my dimmable T-5 unit. I bought new bulbs, did the burn in, and began replacing them, two per week (using a six bulb unit). My acros continued to decline. Other corals in the tank, BTW, were/are thriving, including two stylophora, several birdsnest, leptoseris, chalices, turbinaria, and LPS that I spot feed (an elegance coral, two lord acans, and a large plate). Montipora, psammocora, zoas, and pulsing xenia look healthy but grow very little. There is some red coralline algae, a tiny bit of cyano, and a moderate amount of snotty brown dinos. The tank is two years old, I do regulary water changes (usually 8 gallons every 8 to 10 days, although I have recently stretched it to 14 days). I test alk and salinity daily (9.5 dkh and 1.026), calcium weekly (approx. 430), and Nitrate (undetectable), phosphate (undetectable), mag. (approx. 1400), strontium, and pH (8.3) occasionally.

The verdict is still out on the bulbs, and I have ordered a PAR meter to solve that mystery and eliminate future guesswork as to when the T5 bulbs are toast. Because my nutrients are so low, I started feeding the fish and corals more heavily. This seemed to make all the corals in the tank happy (and the ****ing dinos and cyano) but not the acros. Now, thinking that the problem might be due to nitrates and phophates being out of balance, i.e. too much PO4 not enough NO3, I began dosing potassium nitrate 11 days ago. For the first four days I used Flourish Nitrogen (potassium nitrate and urea) and dosed as per the instructions. A hulk lepto and a turbinaria both bleached, so thinking that it might be due to the urea, I switched to Spectricide stump remover, which is supposedly just potassium nitrate. I mixed with freshwater (2 cups H2O to two tablespoons Spectricide, a per Russ and Twillard, the NO3 dosing experts), then added a few ml. to a pint of tank water and added some expendable invertebrates and coral, just in case, because, afterall, it is stump killer. All expendables survived, so I began dosing 2 ml. per day.

Eleven days later, my nitrates, as of yesterday (unable to test today, because my Salifert NO3 60 tests/kit test kit only provided enough liquid reagent for 45 tests), are approx. 1 ppm. Thus far, I'm really pleased with the results. Coralline algae growth has gone crazy, particularly the purple variety, of which the tank previously had very little. The xenia, zoas, and lps are actually growing (I've had a psammocora frag for 1.5 years with no growth and so-so color that as grown almost a quarter inch and now has a pretty green rim). Montiporas are also finally growing. As for the acros, about half are recovering (with new growth), while the other half continue to stn. Several corals never stn-ed and are now showing good PE, including a pearlberry, a plana, an Oregon tort, and a few other torts and millies. Unfortunately, it appears that I'm going to lose a large spathulata frag that I've had for over a year. One large acro frag that was added a week before I started dosing and a small red plant colony added last week look great with full PE. Also, seeing better coloration in remaining acros. And what little cyano I had appears to be dwindling. Also, snotty brown dinos have been eradicated. Repeat, snotty brown dinos are dead.

For now, I plan to contintinue dosing NO3 in this tank. Hopefully, the potassium will not become a problem. Randy, can you confirm?

 

[CastAway]

NO3 holding steady at 1ppm. Might just be wishful thinking, my eyes playing tricks, but I think I see some deepening color in all my SPS, and improved PE as well. Excited!

 

[Mark75]

@CastAway ,...any changes?

 

[CastAway]

@Mark75, as of tonight, still holding steady at 1ppm. I'm amazed at how it's held fast at 1, not having dosed since the 12th (10ml).

I dosed another 10ml this evening to see what that might do. Will test in an hour or two to see.

Not my eyes playing tricks though, definitely some improved color and notable growth in my SPS - most notably in a Cali tort, a pink lemonade that had seemed to have stalled out, and a new pearlberry I just got.

I'm a believer!

My tank is very sparsely populated, very, so I'm really excited about this.

One thing, might be related, I have no idea, my rocks are not as purple. Might be my eyes though, paranoia maybe. Going to have to read up on coraline and NO3.

 

[Mark75]

That is great Jeff! Color and growth, have you had any problems with algae?