Dosing Nitrate to reduce Phosphate

so I would like to try dosing nitrate but having a hard time figuring out what dosage to start with. looking to have around 1ppm nitrate dosage to 170gallon total system water that will hopefully be in balance with the 60mls of vinegar dosage im already doing. if not carbon will be adjusted to be closer to redfield ratio.

2 grams will do it.
 
does it settle? if I mix 100grams in 100mls of RO water and dose with my pump 2mls per day would that give me an accurate dosage? thanks for input.
 
Potassium nitrate, once dissolved, will not settle in a solution unless it recrystallizes from a supersaturated solution.

But 100 grams solid will not dissolve in 100 mL water at room temperature.

Here's a graph:
http://www.nakka-rocketry.net/knpurify.html

from it:

kno3_solubility.gif
 
Potassium nitrate, once dissolved, will not settle in a solution unless it recrystallizes from a supersaturated solution.

But 100 grams solid will not dissolve in 100 mL water at room temperature.

Here's a graph:
http://www.nakka-rocketry.net/knpurify.html

from it:

kno3_solubility.gif


Randy,

This poor sap is having a major problem. I tried pming you, but it will no let me. Here is the link to the thread. I have extensive knowledge on water purification, but do not feel comfortable giving him advice on his algae problem.

http://www.reefcentral.com/forums/showthread.php?t=2393259&highlight=mixed+bed

Thank you!

Jeremy
 
Any of you guys still dosing NO3? I'm having a bad hair algae issue in my 40br. Through various processes, I've decided the hair algae is feeding off of bound PO4 in my rock, which was mostly dry from Marco rocks. It has been in the aquarium for over a year with a couple of live pieces for seeding. I use Elos for NO3 and Salifert for PO4, but the tests never turn enough of a color for me to conclusively say I have 1ppm NO3 or .03ppm PO4. I've gone BB, added a refugium with various macro algae, more cleanup crew, added a lawnmower blenny, and even mollies (yes, google it) to no avail. After this thread, I'm wondering if dosing C and NO3 would force the bacteria to feed on the bound PO4 in the rock, effectively out competing the hair algae for the PO4. Thoughts?
 
Any of you guys still dosing NO3?

I still dose it everyday. I stopped for awhile, but have started again since I setup a reactor (the zeovit type) that flushes itself on a timed basis.

I dose 10ML of a solution that is comprised of 1 tsp of Potassium, Magnesium and Calcium Nitrate dissolved in 800ML of RODI.

When I was not dosing nitrate, my NO3 was 1 ppm, but my PO4 was always stubbornly high. Now my NO3 is 3 ppm, but my PO4 slowly drifted down and all my algae faded away.

I am experimenting with dosing less nitrate and adding some iron as that can also be a limiting nutrient (for bacteria).

Dennis
 
Any of you guys still dosing NO3? I'm having a bad hair algae issue in my 40br. Through various processes, I've decided the hair algae is feeding off of bound PO4 in my rock, which was mostly dry from Marco rocks. It has been in the aquarium for over a year with a couple of live pieces for seeding. I use Elos for NO3 and Salifert for PO4, but the tests never turn enough of a color for me to conclusively say I have 1ppm NO3 or .03ppm PO4. I've gone BB, added a refugium with various macro algae, more cleanup crew, added a lawnmower blenny, and even mollies (yes, google it) to no avail. After this thread, I'm wondering if dosing C and NO3 would force the bacteria to feed on the bound PO4 in the rock, effectively out competing the hair algae for the PO4. Thoughts?

I really don't think dosing no3 is the appropriate action for you.. Your levels are pretty low already..
I think you should be looking at other possible causes for your algae... Source water? Lighting? Flow? Enough algae eaters?
 
I really don't think dosing no3 is the appropriate action for you.. Your levels are pretty low already..
I think you should be looking at other possible causes for your algae... Source water? Lighting? Flow? Enough algae eaters?

I agree.
I tried nitrate dosing to lower my phosphates and it just didn't make much of a difference (in the cyanobacteria, in my case).

I finally found lanthanum chloride to be the best solution to lowering my phosphates. I didn't use it this way, but ATM is now selling it as a product called "Agent Green" or something like that. I've never used that product am not endorsing it (I used lanthanum from a pool supply store), but am just pointing out that it's probably safe to use, since I doubt ATM would risk their reputation on something unsafe.
 
originally Posted by stancfii Any of you guys still dosing NO3

originally Posted by stancfii Any of you guys still dosing NO3

I stopped dosing NO3 because I got tons of hair algae about 4 months after I started using it. it took me about a year to get all the hair algae out of the tank. I'm using an algae turf scrubber and GFO since.
 
I still dose it occasionally to keep Nitrates at 2-3ppm. If you are dosing nitrate to maintain a low level of 1-3ppm, there is is no real downside that I have found. Any excess Nitrate will be broken down to Nitrogen if you have adequate biological filtration.

No matter the anecdote, judicious dosing of a small amount of nitrate will not cause "tons and tons" of hair algae or a problem that takes a year to rectify. That sort of problem comes from Phosphates and/or inadequate biologic processes in a tank. Unlike Nitrate, Phosphate can bind to rocks and sand and be slowly released for a very long time, fueling algae outbreaks.
 
Adding nitrate or other forms of nitrogen( ammonium, nitrie,ammino acids) even at low levels can result in increased niusance algae. IME. some algae are likely be limited by a lack of it and/ or a lack of soluble reactive phosphate(SRP, inorganic and bioavalaible organic phosaphate ) and/or iron.
FWIW NO3 in my aqariums NOP3 runs at around 0.2ppm(per Salifert) with PO4 .02 to 0.04 ppm( per hanah 713) with very little nuisance alge. Adding enough sodium nitrate to raise the NO3 level to 1ppm did result in a bump in nuisance algae without any reduction in PO4 levels.
 
Maybe I wasn't entirely clear. Your addition of Nitrate may have indeed resulted in increased algae growth, but once you stop adding Nitrate the NO3 level will quickly stabilize to normal levels. In your case, for example, adding Nitrate to raise the level to 1ppm should have easily reversed itself and dropped back down to your normal 0.2ppm value in a week or two max.
Nitrate is not sequestered in the tank like phosphate. It is entirely removed when broken down by bacterial action, becoming nitrogen gas. Therefore, it is an easily reversible addition.
My issue was with the anecdote of nitrate addition causing tons of hair algae which took a year to remove. In the same anecdote the fix was to use GFO and an algae scrubber, both of which are an effective phosphate(not nitrate) removal method.

Sharing that the addition of nitrate to a system with phosphates did not reduce the level of phosphates is a valuable addition to the conversation. The more points of data, the better - we can ask why didn't it work in your case while not working in others? In my system, there have been times when the levels of phosphate rose even when there was 2-3 ppm of nitrate and a good carbon source. At the current time, the relationship between the relative Nitrate and phosphate values is pretty clear and predictable.

I had not tested for nitrate for quite a while(it was pretty steady at 3ppm without additions of nitrate) and about 2 or 3 weeks ago I checked it. I was at 0.2ppm, and surprised how low it had dropped. I checked the phosphate level and was shocked that the value had risen from 0 to 0.06ppm. I saw 0s on every test for months before that. I added 1/8tsp dry CaNO3 to the system, enough to raise the level to 2ppm. A day later I added 1/16tsp to target 3ppm.

After a week I tested phosphate and was already down to 0.04ppm with no other changes to the tank or routine. I checked the nitrate value again and noted that it was once again below 1ppm. I bumped the value up again to ~3ppm with another 1/8 tsp and checked again afar 4 days, phosphate was now down to 0.03ppm. I expect that once phosphate drops a bit further, the nitrate values will stabilize and further additions will be very infrequent.
 
It is entirely removed when broken down by bacterial action, becoming nitrogen gas.
A lot of the N is taken up by organics( bacteria, algae ,corals etc) via assimilation and recylced in the aquarium.Some NO3 is present in most tanks ;some at persistent elevated levels when the nitrogen inputs vs the export methods (skimming out bacteria, harvesting macro algae, using a dinitrator mechanical filtration and cleaning,water changes, etc.) NO3 would never build up in a tank if it is entirely removed as N2.If N was entirely removed life would stop.

Therefore, it is an easily reversible addition.

If the amount of bacteria engaged in anaerobic activity don't change and everything else on the export side and on the input side stays the same,foods,fish respiration and urination for example ; the extra NO3 could hang in for a long while. Many tanks have elevated NO3 levels that persist for long periods of time without an intervention like a sulfur denitrator or large water changes.

Further, the hetertrophic bacteria associated with organic carbon dosing take up N form ammonia directly as well as nitrate,so the acutal amount of nitrate in play to support anaerobic activity may be relatively small since there is less ammonia to oxidize. When you dose the NO3 it will may take some time for the bacteria to respond assuming they are not limited by a another nutrient like SRP or iron or physical condition.

My issue was with the anecdote of nitrate addition causing tons of hair algae which took a year to remove. In the same anecdote the fix was to use GFO and an algae scrubber, both of which are an effective phosphate(not nitrate) removal method.

Limiting the PO4 to very low levels will limit the nuisance algae; limiting the nitrogen will as well. increasing either in the presence of the other will encourage algae to grow .

A turf scrubber or macro algae in a fudge will take up PO4 and nitrogen effecting NO3 levels.

A deficiency of one or the other will prevent a reduction of either by biological uptake as well. However, NO3 and PO4 can be extremely low without such a deficiency, given the other nitrogen sources like ammonium et alia in a fed tank along with unmeasured reactive organic phosphate.

I think the addition of a nitrate source will have variable effect on PO4 , algae growth ,bacteria etc depending on a number of conditions in a given tank.

BTW, surface reef waters hold 0.2ppm NO3 and only 0.005ppm PO4. Personally, my tanks run well at .02ppm PO4 to 0.04ppm PO4 and barely detectable NO3 and there are oligotrophic ages that flourish.

"Nutrient fixing" may be worth a shot for some tanks but in most cases it will spur on nuisance algaeand may take some time to correct if it's overdone.
 
It is entirely removed when broken down by bacterial action, becoming nitrogen gas.
A lot of the N is taken up by organics( bacteria, algae ,corals etc) via assimilation and recylced in the aquarium.Some NO3 is present in most tanks ;some at persistent elevated levels when the nitrogen inputs vs the export methods (skimming out bacteria, harvesting macro algae, using a dinitrator mechanical filtration and cleaning,water changes, etc.) NO3 would never build up in a tank if it is entirely removed as N2.If N was entirely removed life would stop.

Therefore, it is an easily reversible addition.

If the amount of bacteria engaged in anaerobic activity don't change and everything else on the export side and on the input side stays the same,foods,fish respiration and urination for example ; the extra NO3 could hang in for a long while. Many tanks have elevated NO3 levels that persist for long periods of time without an intervention like a sulfur denitrator or large water changes.

Further, the hetertrophic bacteria associated with organic carbon dosing take up N form ammonia directly as well as nitrate,so the acutal amount of nitrate in play to support anaerobic activity may be relatively small since there is less ammonia to oxidize. When you dose the NO3 it will may take some time for the bacteria to respond assuming they are not limited by a another nutrient like SRP or iron or physical condition.

My issue was with the anecdote of nitrate addition causing tons of hair algae which took a year to remove. In the same anecdote the fix was to use GFO and an algae scrubber, both of which are an effective phosphate(not nitrate) removal method.

Limiting the PO4 to very low levels will limit the nuisance algae; limiting the nitrogen will as well. increasing either in the presence of the other will encourage algae to grow .

A turf scrubber or macro algae in a fudge will take up PO4 and nitrogen effecting NO3 levels.

A deficiency of one or the other will prevent a reduction of either by biological uptake as well. However, NO3 and PO4 can be extremely low without such a deficiency, given the other nitrogen sources like ammonium et alia in a fed tank along with unmeasured reactive organic phosphate.

I think the addition of a nitrate source will have variable effect on PO4 , algae growth ,bacteria etc depending on a number of conditions in a given tank.

BTW, surface reef waters hold 0.2ppm NO3 and only 0.005ppm PO4. Personally, my tanks run well at .02ppm PO4 to 0.04ppm PO4 and barely detectable NO3 and there are oligotrophic ages that flourish.

"Nutrient fixing" may be worth a shot for some tanks but in most cases it will spur on nuisance algaeand may take some time to correct if it's overdone.
I don't think we are disagreeing here, its more splitting hairs. If your tank runs at a stable nitrate value close to 0 with a carbon dosing system, and you added a small amount of nitrate to bring the level up to a couple of ppm, stopping the addition of nitrate won't lead to continuing increases in the value. If, however, Nitrate was added to a tank that already has issues fixing nitrate then the addition of Nitrate is unwarranted and will just accelerate the problem.

I think some folks want a quick fix and see the bullet points of this discussion and just add nitrate no matter what, thinking it will solve a phosphate issue.

I have tried to be careful in delineating the distinction, but it is sometimes misunderstood. If you have a new tank and you don't yet have stability, Nitrate addition is not a good idea. If you are not carbon dosing, adding Nitrate is also not justified. Personally I have always had a hard time keeping Nitrate higher than 1ppm, and I have always been utilizing a form of carbon dosing. I attribute that to an effective system setup and export mechanism. What originally led me to dosing was that when it went undetectable, my corals became pale and stressed. The color of my corals is much richer and they have done much better with a little bit of nitrate in the system.

Personally I have not seen any increase in algae growth with nitrate in the system, and there are many other tanks here that have seen the same thing, however, each tank's dynamic is different. Thanks for the continuing discussion of this topic:)
 
Mhucasey, maybe not the best place to ask this but I noticed you use a 'conical settling tank' to your skimmer..
Can you elaborate or do you have a link?
Thanks!
 
Just wondering.. Following redfield ratio..
I have a monster ball of cheato in my system, as well as all in one pellets running.
My last test showed .15 P (Elos High Res.) and 0 N (Red Sea Pro)
Does it make sense to assume that cheato would consume more n than p based on redfield and therefor by my removing the cheato, I might liberate some n so that the pellets could pull down the p a little more?
Any sense to this?
 
I don't think we are disagreeing here, its more splitting hairs. If your tank runs at a stable nitrate value close to 0 with a carbon dosing system, and you added a small amount of nitrate to bring the level up to a couple of ppm, stopping the addition of nitrate won't lead to continuing increases in the value. If, however, Nitrate was added to a tank that already has issues fixing nitrate then the addition of Nitrate is unwarranted and will just accelerate the problem.

I think some folks want a quick fix and see the bullet points of this discussion and just add nitrate no matter what, thinking it will solve a phosphate issue.

I have tried to be careful in delineating the distinction, but it is sometimes misunderstood. If you have a new tank and you don't yet have stability, Nitrate addition is not a good idea. If you are not carbon dosing, adding Nitrate is also not justified. Personally I have always had a hard time keeping Nitrate higher than 1ppm, and I have always been utilizing a form of carbon dosing. I attribute that to an effective system setup and export mechanism. What originally led me to dosing was that when it went undetectable, my corals became pale and stressed. The color of my corals is much richer and they have done much better with a little bit of nitrate in the system.

Personally I have not seen any increase in algae growth with nitrate in the system, and there are many other tanks here that have seen the same thing, however, each tank's dynamic is different. Thanks for the continuing discussion of this topic:)

100% my thoughts too..:)
 
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