Phosphate vs Nitrate depletion

[AJsReef]

Hi all,

Im curious to learn more about your experiences with phosphate consumption vs nitrates. In my current system maintaining detectable levels has been difficult for both parameters.

Through daily dosing of Brightwell Neo products and use of Hanna checkers I’ve been able to find my average NO3 consumption is about .575ppm per day. However, I still have yet to identify a trend in PO4 usage. Using Brightwell instructions I should see a .01ppm increase per ~7.5ml dosed. I’ve increased this dosage to slowly to 20ml daily and still haven’t seen an increase beyond 0 on the Hanna ULR checker.

Based on Nitrate results would it be relatively safe to assume a ratio (10:1) NO3 PO4. Meaning I should attempt to dose >.05ppm/day of PO4 in order to have detectable levels of phosphate?

Likely overthinking here, but really trying to prevent the constant “0”

 

[GillMeister]

Funny, I have the same issue. Constantly at 0 for N and P. I dose nitrate every 3rd day and cannot get phosphate readings no matter what I try. I think reef roids gives me a very temporary phosphate boost but I haven't been able to measure how much.

12 years ago I would have cheered having no N or P. How times have changed.

 

[AJsReef]

Funny, I have the same issue. Constantly at 0 for N and P. I dose nitrate every 3rd day and cannot get phosphate readings no matter what I try. I think reef roids gives me a very temporary phosphate boost but I haven't been able to measure how much.

12 years ago I would have cheered having no N or P. How times have changed.

Literature and understanding around ULNS has certainly changed. I remember chasing 0 as well. Last few years though for me the common denominator seems to be the “low nutrients” testing 0s has me super nervous. Just not sure I should be though.

Im not sure what road I should take. Dose some PO4 even if it’s not detectable knowing at least it was available. Or up dosage until it is detectable which could have its own issues (overdosing, etc)

 

[GillMeister]

Literature and understanding around ULNS has certainly changed. I remember chasing 0 as well. Last few years though for me the common denominator seems to be the “low nutrients” testing 0s has me super nervous. Just not sure I should be though.

Im not sure what road I should take. Dose some PO4 even if it’s not detectable knowing at least it was available. Or up dosage until it is detectable which could have its own issues (overdosing, etc)

What are you using to increase phosphate? I haven't found a supplement to dose yet. I just rely on what I feed my fish and coral.

 

[AJsReef]

What are you using to increase phosphate? I haven't found a supplement to dose yet. I just rely on what I feed my fish and coral.

Brightwell NeoPhos currently, I've tried DIYing it in the past but wanted something "precise" for testing... Increasing feeding seemed limitless lol

 

[Randy Holmes-Farley]

The ways that phosphate and nitrate get consumed in a tank starting at 0 ppm of both are not connected. There's no reason to treat them in a related fashion.

Thus, you may have massive demand for phosphate as it binds to bare calcium carbonate surfaces, but little demand for nitrate.

Likewise, you may have substantial need for nitrate that is being consumed at least partly by denitrification, a process that doesn't consume phosphate.

 

[Randy Holmes-Farley]

Brightwell NeoPhos currently, I've tried DIYing it in the past but wanted something "precise" for testing... Increasing feeding seemed limitless lol

DIY is not precise? lol

You might want to rethink that.

As best I can tell, Brightwell does indicate the composition, concentration, or purity of Neophos.

If you use food grade sodium phosphate, you know all of those things.

 

[Randy Holmes-Farley]

What are you using to increase phosphate? I haven't found a supplement to dose yet. I just rely on what I feed my fish and coral.

Food grade (or other high grade) sodium phosphate. Second best is potassium phosphate.

 

[AJsReef]

In regards to establishing P04 usage baseline, is there a recommended daily increase amount to avoid spiking?

DIY is not precise? lol

You might want to rethink that.

As best I can tell, Brightwell does indicate the composition, concentration, or purity of Neophos.

If you use food grade sodium phosphate, you know all of those things.

In a perfect world with correct tools I don't disagree. I found the scales I tried were wildly fluctuating in measuring the small amounts needed to mix sodium phosphate. The brands of sodium phosphate I attempted to buy were almost always partially/fully solidified into a large mass complicating the process as well.

Any recommended solutions so I could be more precise DIYing?

 

[saltwaterpicaso]

these tanks that are reading constant 0 what kind of equipment are you running in the sump. are you dosing vodka or the such to drive it down. frequent water changes. when my tank runs absolute zero its always bacteria driven.

 

[Randy Holmes-Farley]

In regards to establishing P04 usage baseline, is there a recommended daily increase amount to avoid spiking?

Not really. If you dose 0.03 to 0.05 ppm daily, that is generally fine. If it stays at undetectable after a week or two, and if you believe your test, then raising it is fine. Too low of phosphate is apparently worse than too high.

In a perfect world with correct tools I don't disagree. I found the scales I tried were wildly fluctuating in measuring the small amounts needed to mix sodium phosphate. The brands of sodium phosphate I attempted to buy were almost always partially/fully solidified into a large mass complicating the process as well.

Any recommended solutions so I could be more precise DIYing?

I think a teaspoon and a measuring cup are plenty accurate enough since you titrate the amounts dosed based on tests anyway, and "calculations" of what is needed are of limited value for phosphate dosing. Really, they only prevent massive overdosing by math mistake.

This is a good brand:

Sodium Phosphate Dibasic 4 Oz Food Grade Fine Powder USA SELLER | eBay

Sodium Phosphate Dibasic. The item for sale is 4 Ounces (by weight) of Sodium Phosphate Dibasic. Fine Powder. • Anti-Caking Agent. • Thickening Agent. • Water Softener.

www.ebay.com

 

[AJsReef]

these tanks that are reading constant 0 what kind of equipment are you running in the sump. are you dosing vodka or the such to drive it down. frequent water changes. when my tank runs absolute zero its always bacteria driven.

No bacteria dosing, roller mat with bypass full open (Clarisea) and undersized skimmer tuned to pull minimal skim

 

[saltwaterpicaso]

how about water changes how often if its weekly i would try bi weekly if longer i would go longer just to see what happens. how often are you feeding the fish

 

[AJsReef]

how about water changes how often if its weekly i would try bi weekly if longer i would go longer just to see what happens. how often are you feeding the fish

I do continuous W/Cs of 2gpd (180 ish gallon system) for 30% month

In recent weeks when attempting to increase PO4/NO3 I've been feeding frozen food 4+ times a day and a couple sheets of nori. Fish seem extremely happy and well fed Acros don't look unhappy but PE isn't the greatest and I've had issues previously by what I assume resulted from bottoming nutrients (dyano crash). For piece of mind I just want to get to some stabilization of detectable levels.

I did purchase the Hanna standards to confirm calibration on each tester.

 

[AJsReef]

Not really. If you dose 0.03 to 0.05 ppm daily, that is generally fine. If it stays at undetectable after a week or two, and if you believe your test, then raising it is fine. Too low of phosphate is apparently worse than too high.



I think a teaspoon and a measuring cup are plenty accurate enough since you titrate the amounts dosed based on tests anyway, and "calculations" of what is needed are of limited value for phosphate dosing. Really, they only prevent massive overdosing by math mistake.

This is a good brand:

Sodium Phosphate Dibasic 4 Oz Food Grade Fine Powder USA SELLER | eBay

Sodium Phosphate Dibasic. The item for sale is 4 Ounces (by weight) of Sodium Phosphate Dibasic. Fine Powder. • Anti-Caking Agent. • Thickening Agent. • Water Softener.

www.ebay.com

Thanks for time and recommendation, I see the anti-caking agent listed which is already a step forward.

Are the mixture ratios consistent across Sodium and Potassium phosphate? Would "James Planted Tank" calc be usable?

 

[Randy Holmes-Farley]

I did purchase the Hanna standards to confirm calibration on each tester.

Just to be clear, Hanna color standards in a sealed vial only test the electronics, not the reagents, user procedures, scratched vials, etc.

 

[Randy Holmes-Farley]

Thanks for time and recommendation, I see the anti-caking agent listed which is already a step forward.

Are the mixture ratios consistent across Sodium and Potassium phosphate? Would "James Planted Tank" calc be usable?

Yes, that's the calculator I'd use, and I'd use any sodium or potassium phosphate interchangeably in it, even though that is not technically "perfect".

 

[saltwaterpicaso]

with todays equipment and how much bacteria is in our tanks i would cut back on the water change i do 50 percent water change every 3 months just to replace whatever elements i cant test for. the water i take out goes in my frag tank not a single issue been doing it for years.

 

[hart24601]

I have had both phosphate and nitrate limitation in the past. My older system which was fed a great deal, seemed to thrive on undetectable phosphates, my mari acros would start to brown out when levels started creeping up - on this system I noticed pale colors and noticed I had 0 nitrate, I dosed nitrate and colors became more vibrant. It was clear and dramatic with no other changes. Phosphate i kept at or near 0 detectable.

Fast forward 6 years and I had some brown dry looking acros and also some bleached and faded corals. I did have detectable nitrate in this system but phosphate was 0. Now being that I use an autofeeder 6x a day plus other foods like easy sps on a doser I assumed phosphate limitation wasn't possible with the huge import and export in the system.

However I decided to start dosing phosphate, I (at that time) had a huge amount of chateo and some large clams. I slowly and skeptically started dosing phosphate - it took a whole bottle of neophos to get levels delectable. To my amazement the brown dry looking corals started looking better and color started returning to the bleached coral. I was absolutely shocked as this seemed nearly contrary to my previous experience. After keeping phosphate on a doser a while I removed the chaeto and the system has totally recovered with no other changes. I can only assume the clams I have suck up the phosphate, but with the large feedings I really didn't think this possible particularly the seemingly two phenotypic results with some acro dry and brown, others pale, but it sure was.

I still am dosing neophos and assume I will need to keep doing that because, at least in part, because of the clams. I would like to get phosphate to 0.1 at Hans warner recommends, but it seems to be holding at around .05 give or take for a couple months now so I don't want to mess with things more.

 

[LDog74]

I do continuous W/Cs of 2gpd (180 ish gallon system) for 30% month

In recent weeks when attempting to increase PO4/NO3 I've been feeding frozen food 4+ times a day and a couple sheets of nori. Fish seem extremely happy and well fed Acros don't look unhappy but PE isn't the greatest and I've had issues previously by what I assume resulted from bottoming nutrients (dyano crash). For piece of mind I just want to get to some stabilization of detectable levels.

I did purchase the Hanna standards to confirm calibration on each tester.

I had the same issues zero NO3 & PO4 & eventually ended up getting Dino's. Also lost a couple of corals because of no nutrients over several months. I was doing 2.5gal auto water change per night. I started using Loudwolf sodium nitrate & trisodium phosphate per http://theplantedtank.co.uk/calculator.htm. Made minor additions slowly with both of these. Checked both levels every day for a month. After the first week had levels to NO3 .03-.05 & PO4 .03-.6. Would check twice a day the first week or so because the levels would drop in the morning, not always to zero but in the low range. I also stopped the auto water changes during this time. Fed heavy twice a day LRS fish frenzy.
After a month of doing this (I also vacuumed the sand twice a day with a 1 micro sock to remove the dinos). Dino's are gone, corals have never looked better, great growth, color & PE. My levels are NO3 .10-.25 & PO4 .05-.10 & holding with in the range. I started the auto water changes back up after about 30 days of holding the range now 2 gal per night. Tank is 225 display w/40 gal sump.
Hope this help. I still test PO4 every day & NO3 every other & will for a couple of months. I don't want to deal w/ dino's again. Reagents are inexpensive vs lost corals.
FYI my tank is now 1 year old. Problems started 8 months in.

Hope this helps! Good luck.