Phosphate vs Phosphorus

[Dan_P]

Randy - my Hanna ultra low (and Hanna ref PO4 checkers) always comes in at .12 to .2 ppm PO4. Any icp test I’ve done show phosphorus reported in ppm (not PPB) and show I’m at .02 ppm phosphorus. These don’t jive at all on conversion. I don’t have much algae, but my lps are never thriving. All my other parameters are usually good. Any advice?

ICP measurements of P are likely to be wrong ALL the time. The vendors are not being transparent about water sample degradation during transport.

 

[camelon02]

Sorry to hijack this thread a bit, but it was what came up when I was doing a search this morning.

I received my test results from ATI Aquaristik yesterday for my 32 gallon Biocube. It showed Phosphate at undetected and Phosphorus at 1561µg/l against a reference of 11.62 µg/l. I thought this seemed pretty crazy and reading here it seems (unless I missed something, which is entirely possible) even more crazy.

Any ideas on this that I should be looking at? My other numbers from the test all made sense based on what I am doing with dosing and other maintenance.

 

[Randy Holmes-Farley Verified Community Expert]

Sorry to hijack this thread a bit, but it was what came up when I was doing a search this morning.

I received my test results from ATI Aquaristik yesterday for my 32 gallon Biocube. It showed Phosphate at undetected and Phosphorus at 1561µg/l against a reference of 11.62 µg/l. I thought this seemed pretty crazy and reading here it seems (unless I missed something, which is entirely possible) even more crazy.

Any ideas on this that I should be looking at? My other numbers from the test all made sense based on what I am doing with dosing and other maintenance.

Must be a typo. Likely the phosphorus one is wrong, unless phosphate might be close to 5 ppm.

 

[gray808]

g and ulr PO4 checkers have different id/sku Numbers. They both read in ppm. I use both and don’t see a big difference in results..... Hanna makes a calibration fluid to check accuracy, but there is no way to calibrate Hanna checkers.

Hmmm. My Hanna Phosphorus ULR says it reads in PPB:

--Gray

 

[Randy Holmes-Farley Verified Community Expert]

Hmmm. My Hanna Phosphorus ULR says it reads in PPB:

--Gray

Hanna makes multiple ULR P checkers these days:

Saltwater Aquarium Ultra Low Range Phosphorus Colorimeter - Checker® HC

The HI736 Checker®HC (Handheld Colorimeter) provides a simple, accurate and cost effective way to measure phosphorus in marine systems.

www.hannainst.com

Marine Phosphate Ultra Low Range Colorimeter - Checker® HC

The HI774 Phosphate Ultra Low Range Colorimeter in. Checker® HC provides a simple, accurate and cost effective way to measure phosphate.

www.hannainst.com

 

[gray808]

That is Phosphate vs Phosporus. I understand "they are the same" or variations on the same thing. I have both.

The PHOSPHATE ULR reads out in PPM, Parts Per Million.
The PHOSPHORUS ULR reads out in PPB, Parts Per Billion.

Apparently there is some formula to correlate one to the other, but frankly all I care about is "is my reading too high?".

So, to that end:
1) WHICH checker would be the preferred one? Seems to me the Phosphorus ULR would, since it's in PPB.
2) For each checker, what is the upper bound reading, PPM or PPB, where one should start to worry?

 

[debees5]

Hmmm. My Hanna Phosphorus ULR says it reads in PPB:

--Gray

Mine are Phosphate (PO4) ULR and the other is Phosphate (PO4). I do get different readings on them - the ULR reading is generally higher, but they are both ppm. ICP tests report out in Phosphorus (P) ppb, which requires a calculation (1st a multiplier, then change from ppb to ppm). IMO, as long as you know where you want your readings for your tank, it really doesn’t matter if you gauge it with P or PO4.

 

[ReefChasers]

I personally find the phosphorous ULR in PPB to be more accurate than the phosphate ULR PPM so we like to use the phosphorous ULR and just convert the measurement to ppm

 

[Randy Holmes-Farley Verified Community Expert]

That is Phosphate vs Phosporus. I understand "they are the same" or variations on the same thing. I have both.

The PHOSPHATE ULR reads out in PPM, Parts Per Million.
The PHOSPHORUS ULR reads out in PPB, Parts Per Billion.

Apparently there is some formula to correlate one to the other, but frankly all I care about is "is my reading too high?".

So, to that end:
1) WHICH checker would be the preferred one? Seems to me the Phosphorus ULR would, since it's in PPB.
2) For each checker, what is the upper bound reading, PPM or PPB, where one should start to worry?

I'd personally worry more if phosphate was too low, not if it was too high (within reason).

Good target levels (IMO) are 0.01 to 0.1 ppm phosphate (3-33 ppb phosphorus).

 

[BoneDoc]

I accidentally buy the ULR phosphorus for my phosphate checker. Do you guys know if the readings are the same?

 

[DrZoidburg]

I accidentally buy the ULR phosphorus for my phosphate checker. Do you guys know if the readings are the same?

They are not the same. You have to apply a conversion factor to get phosphates. Phosphorous only reads to .6 mg/L +/- 195 ppb, and phosphate 2.5 mg/L I think. Which is 815 ppb+/-.

 

[Timfish]

Just FYI but the Hanna low range phosphorus checker is checking for phosphates then converting to the equivalent amount of phosphorus. It's not testing for, or including organic phosphorus in the results given.

 

[BoneDoc]

Sorry. I meant the phosphorus reagent instead of the phosphate reagent fir my ULR phosphate checker

 

[DrZoidburg]

Sorry. I meant the phosphorus reagent instead of the phosphate reagent fir my ULR phosphate checker

Maybe they would work in a similar way. Both claim ascorbic acid method. However they also maybe are tweaked to work with specific checker. I can't say for sure.

 

[maxwell]

 

[debees5]

Hmmm. My Hanna Phosphorus ULR says it reads in PPB:

--Gray

Phosphate checkers read in ppm, not phosphorus (which read in ppb).

 

[maxwell]

Phosphate checkers read in ppm, not phosphorus (which read in ppb).

I use the above with the table reads 16 but my ICP test always says its no phosphate as its below measuring point . WHO are we supposed to believe ????????

 

[Reefahholic]

I use the Phosphorus ULR because it reads the lowest in PPB.


Hanna Phosphate High Range HI717
Range: 0.0 to 30.0 ppm



Hanna Phosphate Low Range HI713
Range: 0.00 to 2.50 ppm



Hanna Phosphate ULR HI774
Range: 0.00 to 0.90 ppm



Hanna Phosphorus ULR HI736
Range: 0 to 200 ppb

I’ve been able to catch when the tank has bottomed out and dose some nutrients to correct.

 

[Reefahholic]

It’s obvious you have got to have some nutrients in the system.

 

[maxwell]

H

It’s obvious you have got to have some nutrients in the system.

Hi ,
I use the H1736 Phosphorous ULR which measures ppb and use the H1736 reagent . Is this the one you use and what is your target phosphate level as per the chart posted .thanks Bill