hanna phosphate checker question

[Burrito]

i bought the low range phosphate checker and every test i've done comes back as zero, i also have the red sea kit and the few times i've done the phosphate test with red sea its around .04. is the low range just not able to get that accurate or .04 is zero to the hanna checker?

should i buy the ULR checker instead or would it still show zero?

 

[gfordQC]

The ULR checker measures ppb (Parts per Billion) so it will read much lower than the Phosphorus checker which is ppm (Parts per Million)

I use the ULR and am very happy with it.

 

[miPapareef]

The low range Hanna checker is a Phosphate checker with this spec

• Range: 0.00 to 2.50 ppm (mg/L)
• Resolution: 0.01 ppm (mg/L)
• Precision: ±0.04 ppm (mg/L) ±4% of reading @ 25°C

This means if your actual sample is at 0.04 ppm phosphate then it might read 0 and that is within the accuracy range.

The Ultra low range Hanna checker is a Phosphorus checker with this spec

• Range: 0 to 200 ppb
• Resolution: 1 ppb
• Accuracy: ±5 ppb ±5% of reading

To convert ULR Phosphorus in ppb to LR checker Phosphate you do this ( Xppb * 3.066 / 1000 = Xppm)

So converting the ULR spec to Phosphate spec I get

• Range: 0 to 0.61 ppm
• Resolution: 0.003 ppm
• Accuracy: ±0.015 ppm ±5% of reading

This means the ULR is 3 to 4 times more resolution and is more accurate at the ULR.

I use the ULR because my system runs in the ULR. Sounds like you would be better served with the ULR checker.

 

[Burrito]

thansk for the detailed response.. ill look to sell my LR and buy a ULR. practically speaking, for a system (i'm not striving for or against ULN system) is 0-.04 much of a difference for water paramaters?

 

[miPapareef]

is 0-.04 much of a difference for water paramaters?

I think having detectable phosphate in the system is important. I’ve seen some research indicating phosphate constraint is very bad for corals, so I like to keep above 0.03 ppm.

 

[roberthu526]

With the ULR checker I think you will have a reading for sure. My RODI with dual stage DI still shows a number. My tap water TDS is 45 by the way.