Hanna Phosphate or Phosphorus ULR checker?

[ReeferMadness99]

So obviously one measures Phosphate and one Phosphorus. The ULR will give you phosphorus in ppb but how does phosphorus translate to the aquarium hobby where we traditionally measure phosphate? Anyone know the difference?

 

[Widdy]

Hi Felix,

The way I understand it (beware when that happens!) is phosphorus x 3.066/1000 = phosphates. Being that phosphorus meter maxes out at 200ppb which roughly translates to 0.6132ppm (200ppm x 3.066/1000). So if your phosphates are above .60 (I hope no one's is), you wouldn't know with the phosphorus meter, or maybe it'll shoot fireworks; I dunno, I don't have one . Whereas the phosphate meter maxes out at 2.5mg/L (ppm).

I think I read the Hanna ULR is more precise as well (.04 +/- vs .015 +/-).

If I'm wrong, please correct. Would like to get a better understanding myself.

 

[ReeferMadness99]

Okay, thats what I've read too. Just wanted to make sure I wasn't the only one, lol. Thanks Steve!

 

[Boomer]

99

So obviously one measures Phosphate and one Phosphorus

Not really, it is how it is expressed. Think meters vs feet or cm vs in.



Widdy

You are correct It is often referred to as PO4 or PO4-P. Just like ther is NO3- and NO3-N or NO2- and NO2-N. It is common practice in water chem to give them as P or N as the "O" is not a concern in most cases. PO4-P means expressing it as P

The conversions are simple, i.e.,

Molecualr Weigh of:

P = 30.97

O = 15.99

So,

PO4 = 30.973762 + ( 15.99999 x 4) = 94.973725

94.973 / 30.973 = 3.06683

So, 1 ppm P or PO4-P = 3.066 ppm PO4-