Dosing Nitrate to reduce Phosphate

[ReefKeeper64]

For counterpoint:

I think, it's time for a few caveats :

Nitrate is still considered a more of a bane to reef tanks than a benefit. It drives some nuisance algae and perhaps more importantly ,zooxanthelae in corals which often leads to browning and or bleaching .
Tests kits are often imprecise particularly at low ranges. Many tanks run very well with undetectable NO3. Surface ocean water has only 0.2ppm NO3. The bacteria assimilating nitrogen and phosphate may be using other forms of dissolved nitrogen like ammonia.

So, for now until more practical anecdotal information develops, I plan to tweak nitrogen a tiny bit to keep it at 0.2 to 1ppm per the Salifert test kit and observe any changes over several months time .

I second that because excesses in either direction are a misery for any tank. Even statements by chemists are admittedly reporting anecdotal evidence. 0.2 to 1.00 ppm is a good safe bet.

 

[pfoxgrover]

Does anyone know if it is safe to add the sodium nitrate to either solution of 2 Part?

I am afraid to add it to my top off water because I don't want to fertilize standing freshwater and I don't know exactly how much I use. The 2 Part I have on dosing pumps and know the exact amount is pumped.

 

[the_real_brian]

Does anyone know if it is safe to add the sodium nitrate to either solution of 2 Part?

I am afraid to add it to my top off water because I don't want to fertilize standing freshwater and I don't know exactly how much I use. The 2 Part I have on dosing pumps and know the exact amount is pumped.

I mixed solid NaNo3 with distilled water in a gallon jug. I dose with a syringe.

 

[pfoxgrover]

I mixed solid NaNo3 with distilled water in a gallon jug. I dose with a syringe.

I am pretty much doing the same thing with a measuring cup 2 ties a day. I would like to spread the dosage out more, preferably without buying another dosing pump.

My ATO reservoir would work although I only clean it like once a year and cant control the dosage. Will bacteria grow in there like crazy if I add Nitrate to a seldom cleaned reservoir?
That is why I though it may be better in the Alk or CA 2 Part solution.

 

[dkeller_nc]

My ATO reservoir would work although I only clean it like once a year and cant control the dosage. Will bacteria grow in there like crazy if I add Nitrate to a seldom cleaned reservoir?
That is why I though it may be better in the Alk or CA 2 Part solution.

Probably. In theory you can sterilize the ATO container, add a 0.2 um filter to the output of your RODI unit and maintain the reservoir's cleanliness by avoiding inoculating it with bacteria/algae.

In practice, though, it's unlikely you could maintain such sterile conditions, and nitrate is a fertilizer.

If you're using a controller, then adding another dosing pump is $80 (at least from BRS). Seems like an inexpensive investment, particularly considering what an overdose of NO3 could do to your tank.

 

[reefmutt]

TMZ, thanks for that detailed response.
I was running (on reverse daylight) healthy, growing cheato and a brand new sand bed in a sump fed by tank water prefiltered by a filter sock. System is only 4 months old.
My n has been zero from day one and p has been between .06 and .1 while using almost 500-750 ml rowaphos every week! If I left it longer, p would start to go higher
I keep hearing 'well, feed more! Raise the nitrate.' This did not work for me at all..
I started by removing half the sand bed and all of the cheato and tried to feed more. This only made controlling p even more difficult.
In desperation, two days ago, I removed the rest of the sand bed. At the same time I had an ailing sea urchin die. 36 hours after removing the sand completely and about 4 days after removing the cheato (and with a day or two old dead sea urchin) I got a .5ppm reading of n and a shockingly high p level of close to .15.
So, today, I changed the one week old rowaphos and removed the still decaying urchin.
Tomorrow, I will test again for n and p levels and report back. I am hoping that the rowa will bring down my p and over the coming weeks, I will reintroduce cheato (as Tom has indicated, it has more beneficial impact on the system when used on a reverse daylight schedule) and some of my sand bed baskets as needed to try to keep n at or just below 1ppm.... This is ALL assuming (hoping) that p will be better controlled with detectable n in the system... At least this is my plan.... I'll keep you posted!
Thanks again to all the contributors to this thread. It has been fascinating..
Endlessly so, just like this hobby!

 

[mocika]

Tnx for this very useful topic.
I have 75g tank for 1,5 year. My No3 are always 0 and Po4 0.04-0.05. I had a little cyano and i try to dose NaNo3. I dosed for one week and test nitrate with salifert and they are 0.2. Cyano was dissapire. After that i stop dosing NaNo3 my No3 drop and cyano is coming back a little. So this teory is so fine for me.
My problem is disbalanse in No3 and Po4. I would like to reduce Po4 and add a little No3. So what shud i do next?
-turn ATS off because its consuming my No3,
-keep ATS and dosing NaNo3,
-keep ATS add votka for lowering Po4 but also add NaNo3 for nitrate sorce.

TNX inn advance

 

[the_real_brian]

Tnx for this very useful topic.
I have 75g tank for 1,5 year. My No3 are always 0 and Po4 0.04-0.05. I had a little cyano and i try to dose NaNo3. I dosed for one week and test nitrate with salifert and they are 0.2. Cyano was dissapire. After that i stop dosing NaNo3 my No3 drop and cyano is coming back a little. So this teory is so fine for me.
My problem is disbalanse in No3 and Po4. I would like to reduce Po4 and add a little No3. So what shud i do next?
-turn ATS off because its consuming my No3,
-keep ATS and dosing NaNo3,
-keep ATS add votka for lowering Po4 but also add NaNo3 for nitrate sorce.

TNX inn advance

Your ATS is consuming both No3 and Po4. It sounds like it's running out of No3 before your Po4 is reduced to the level you want it. I would just do the same thing you did before, add No3 without vodka and let your ATS do the rest.

 

[herring_fish]

The Redfield ratio has been touched on but then the significance of it actually overlooked.
Wether the ratio is 16:1 or 20:1 or anything in between is actually of little significance.....
Aaroz

Again, I am not an expert on this new experiment but....

From what I have been reading here and from my experiance, raising the nutrient load is not the answer in and of itself. I gather that you need to change the ratio of Nitrates(N) to Phosphates(P). Raising P off the charts can of coarse be harmful to your tank.
Instead, you need to raise N by itself, not getting it too high. There is a Redfield Ratio

You can Google it but we Algae scrubber guys refer to it often. We can argue about whether it is accurate or even valid but as a rule of thumb, it lead me to dramatically lower my P to get the ratio in line, using Phosban. While it worked as advertized, it didn't get P low enough to meet the ratio. 20:0, 16:0 or 4:0 still didn't work.

I had to add N (carefully) and bingo!

 

[mhucasey]

Reference:

bacteria consume iron to survive
http://dnr.wi.gov/topic/DrinkingWater/documents/pubs/ironinwell.pdf

There are plenty of other studies citing how bacteria consume iron and the one above is just the result of a quick bing search. Read up on this as it is a component to understanding the biology behind this PO4 challenge.

Happy Reefing all! :wavehand:

A big thanks to you, ReefKeeper64 on the iron info. I have been dosing nitrate for close to a year now, in fact I was one of the first posters in this thread. After significantly upsizing my skimmer I started seeing a decline in the bacterial response to nitrate, and I saw a serious slowdown in the phosphate reducing part of the equation. I tried re-introducing pellets, tried VSV, etc but while the nitrate would drop, phosphate got no lower than 0.16.

I have dosed iron but very sparingly - part of the reason I don't like GFO is that I've lost clams after introducing it too rapidly - with all signs pointing to iron as the problem.

Anyhow, I significantly upped my dose of Iron, and in less than a week I am down to 0.03 PO4. In researching Iron usage I have read that skimmers can deplete iron and I think my findings can corroborate that. All my overflow water from the display tank passes through the skimmer, so I will need to maintain iron levels moving forward. I am making my own iron citrate solution and so dosing iron is pretty cheap.

 

[reefmutt]

Mhucasey, thanks for the anecdote.. Very interesting, as always..
Which test kit do you use to test iron concentration and what concentration do you shoot for into it aquarium?
Thanks!

 

[herring_fish]

Opptimum Iron Level

Opptimum Iron Level

As an ATS user, I am also interested in the optimum level of iron (Fe or just I). This has always been known as a requirement for good algal growth. I dose I on a hit or miss basses but I have no idea what I should be shooting for.

It seams that the requirements for good bacterial growth is similar to that which is required for good algal growth. I suppose that they both have grown to thrive in the same environment so it is what you would expect.

 

[mhucasey]

I had not been testing for Iron, mainly because I was only minimally dosing iron. I have been dosing the Zeovit iron and maxed out at maybe 1/2 ml per week which is less than one quarter the max dose for my system volume that the bottle lists.

I will be getting a Hannah Iron Checker to ensure that I don't overdose(I love the Hannah checkers!). In the last week or so the increased dosing has showed in a slight greening of a yellow acro, which is good indicator to back off the dose a bit. Seeing this I cut the dosing down and am still seeing the positive bacterial benefits.

 

[ReefKeeper64]

A big thanks to you, ReefKeeper64 on the iron info. I have been dosing nitrate for close to a year now, in fact I was one of the first posters in this thread. After significantly upsizing my skimmer I started seeing a decline in the bacterial response to nitrate, and I saw a serious slowdown in the phosphate reducing part of the equation. I tried re-introducing pellets, tried VSV, etc but while the nitrate would drop, phosphate got no lower than 0.16.

I have dosed iron but very sparingly - part of the reason I don't like GFO is that I've lost clams after introducing it too rapidly - with all signs pointing to iron as the problem.

Anyhow, I significantly upped my dose of Iron, and in less than a week I am down to 0.03 PO4. In researching Iron usage I have read that skimmers can deplete iron and I think my findings can corroborate that. All my overflow water from the display tank passes through the skimmer, so I will need to maintain iron levels moving forward. I am making my own iron citrate solution and so dosing iron is pretty cheap.

I'm glad you saw the same positive results I and my reefing buddies, including Glennf, have seen. This is what you want to insure you have your iron levels at NSW (0.05-0.09ppm). It's a Hanna Iron Checker and its $49. It works like the Hanna PO4 checker and uses its own iron reagent powder. The simplicity and accuracy (+-0.04ppm) can't be beat.

 

[mhucasey]

I think the best way to dose Iron I have seen was presented as part of the so called "DSR" method referred to a few pages back. The idea is to dose, then test < 1hr later. Iron can break down/bind to things quickly and so testing to long after a dose can give some invalid results as i understand.

Build up the dose to the target level of 0.15ppm(the level he uses for DSR, can't beat his results) in increments, don't just dump in a whole bunch at once the first time. Using Iron Citrate should extend the usable life of the iron in the system as the citrate binds to the iron and the bond is broken by high light levels, releasing the Iron.

 

[mocika]

Your ATS is consuming both No3 and Po4. It sounds like it's running out of No3 before your Po4 is reduced to the level you want it. I would just do the same thing you did before, add No3 without vodka and let your ATS do the rest.

Maybe the best combination is to dose NaNo3 for rising No3 and to use GFO or dosing iron for lowering Po4.

 

[DiscusHeckel]

Maybe the best combination is to dose NaNo3 for rising No3 and to use GFO or dosing iron for lowering Po4.

Hi,

What kind of iron are you dosing to lower PO4?

Off-the-shelf chelated iron supplements do not lower PO4. You need to dose a different iron for this purpose.

 

[mocika]

Im not dosing iron atm, i will try first to lower Po4 with GFO first, then maybe will try with iron. ATS also need iron for algae grow so thats is the second reason.

 

[ReefKeeper64]

Hi,

What kind of iron are you dosing to lower PO4?

Off-the-shelf chelated iron supplements do not lower PO4. You need to dose a different iron for this purpose.

What are you suggesting as a different iron? What exactly is this your suggestion for a different iron? I dose an off the shelf liquid iron (brightwell aquatics) and it is effective but I have no affinity to that brand. Its just available from my LFS.

 

[mhucasey]

The DIY Iron Citrate is easy to make and very cheap. I paid 24 bucks for enough raw materials to make at least 5 years worth. Randy uses this DIY supplement among others.