Phosphate: Redsea vs Hanna

[Trevorreilly73]

Hi reefers, I recently got a Hanna ulr phosphate checker. Originally I was using Redsea phosphate test.

On the Redsea test I get no colour change whatsoever.. leading me to believe I have no phosphate.

Using the hanna checker I have 0.27ppm phosphate.. leading me to believe I have way too much.

Has anyone any experience/advise on this?

 

[Randy Holmes-Farley Verified Community Expert]

If you use both on new salt water, what do you get?

 

[Trevorreilly73]

If you use both on new salt water, what do you

If you use both on new salt water, what do you get?

A great question, one I never thought of myself. What is the purpose to testing a batch of freshly mixed saltwater? Contamination coming through the rodi system?

 

[Randy Holmes-Farley Verified Community Expert]

A great question, one I never thought of myself. What is the purpose to testing a batch of freshly mixed saltwater? Contamination coming through the rodi system?

It’s mostly to test the test itself, but it can also point to an ro/di problem.

 

[hsp]

I have a HI774 and noticed weird changes in my tank. So, I did 3 tests in rapid succession using exactly the same methodology as per instructions and got the following results:

0.12ppm

0.06ppm

0.08ppm

I shared this with Hanna support and was told:

Have you considered the following:

• Are there any scratches/marks on the vials? You may need to purchase new vials
• Are you ensuring there are no finger marks or that the vial is wiped dry properly?
• Have you verified using the calibration check set i.e. HI774-11?
• Have you done 3 tests of the same sample taken? The accuracy of the checker is ±0.02 ppm ± 5% of reading.

Failing all the above attempts, you may have to purchase a new replacement as the HI774 checker is out of warranty.

I think in my case some scratches on the vials caused the issue.

 

[Randy Holmes-Farley Verified Community Expert]

Yes, orientation of cuvettes is very important if they have any defects.

 

[Dburr1014]

Hi reefers, I recently got a Hanna ulr phosphate checker. Originally I was using Redsea phosphate test.

On the Redsea test I get no colour change whatsoever.. leading me to believe I have no phosphate.

Using the hanna checker I have 0.27ppm phosphate.. leading me to believe I have way too much.

Has anyone any experience/advise on this?

I could never get a good reading with redsea either.
Hanna is they way to go if you can.

 

[AngelFly]

I also at wits end I can't seem to get valid Phosphate test result. I have Red Sea tester and seem to get .12-.16ppm consistently. I hate color testers, hard to read. So bought the Hanna tester. It always gives me .90ppm. Manual says to "Dilute and re-run". That makes no sense to me. As I dilute sure number goes down. How am I suppose to get valid reading . More I dilute less of reagent of-course the reading will lower. I just added 60 drops of Phosphate Rx to 100gal tank. Readings should have lowered by .5ppm per 10gal . Readings haven't changed. Ideas please ? One packet of the Hanna seems too large. However I did notice color change in Hanna curvette after first 30drops - waited 24hrs, added another 30drops retested. Hanna same result .90ppm.
Ideas , how can I get Hanna tester to work?

 

[Justfebreezeit]

I also at wits end I can't seem to get valid Phosphate test result. I have Red Sea tester and seem to get .12-.16ppm consistently. I hate color testers, hard to read. So bought the Hanna tester. It always gives me .90ppm. Manual says to "Dilute and re-run". That makes no sense to me. As I dilute sure number goes down. How am I suppose to get valid reading . More I dilute less of reagent of-course the reading will lower. I just added 60 drops of Phosphate Rx to 100gal tank. Readings should have lowered by .5ppm per 10gal . Readings haven't changed. Ideas please ? One packet of the Hanna seems too large. However I did notice color change in Hanna curvette after first 30drops - waited 24hrs, added another 30drops retested. Hanna same result .90ppm.
Ideas , how can I get Hanna tester to work?

Which hanna tester?

 

[AngelFly]

Hanna HI774 . Just bought new reagent good until 3/27

 

[Justfebreezeit]

Only other thing i can think of is make sure you have a good consistent tecnique.

I always face the cuvette the same direction. I face the 10ml mark forward everytime. Make sure its a clean cuvette and smudge free. I use kimtech wipes off Amazon for the exterior. And you are getting most of the reagent in which is a powder and not drops. (Maybe you mixed up the hanna and red sea names in your explanation)

My results have been within the .02 error margin pretty consistently.