Possible to have zero Po4??

[cracker]

Hello, I got my Ulr Hanna checker yesterday . I tested the 75 & got a zero !
Then I tested the 18o & came up with 0.006 (using the conversion chart) .
So earlier today I tested the 75 again & got another zero!
Now both these tanks have been always been nutrient deficient But I never expected a zero read from a url checker! Any way I'm slowly dosing Seachem Phos to brings these numbers up
Just wondering how unlikely to have real close to zeros ! I do of course have algae so there is something in there !

 

[Dr. Reef Verified Sponsor]

I dose lanthanum so I always get 0 on phos using ULR. I have cut back on dosing in order to get a little on phos. I am only dosing a drop or 2 of highly diluted mixture.
I also have some algae in tank so I am assuming the accuracy window of the checker is at play and 0 may not mean absolute 0 and could be 5% up or down.

 

[mcarroll]

Hello, I got my Ulr Hanna checker yesterday . I tested the 75 & got a zero !
Then I tested the 18o & came up with 0.006 (using the conversion chart) .
So earlier today I tested the 75 again & got another zero!
Now both these tanks have been always been nutrient deficient But I never expected a zero read from a url checker! Any way I'm slowly dosing Seachem Phos to brings these numbers up
Just wondering how unlikely to have real close to zeros ! I do of course have algae so there is something in there !

No need to wonder – the instruction manual may have both the accuracy and precision rating for the tester. Often it's something like +/- 0.02 ppm or +/- 10% of the reading.

0.00 and 0.006 are both effectively zero. Real zero. As in there's nothing that the meter tests for in the water.

It's still a symbolic reading since there are exotic forms of phosphate still in the system, but if you're reading zero's AND seeing "trouble" of one kind or other in the tank, then it's fair to look here first or early in your troubleshooting.

 

[MTBake]

I've seen 0 with my ulr checker as well. Had issues with pale coloration on sps. I try to keep mine around 40ppb using the checker.

 

[cracker]

I forgot about the +or - factor so I'll "slowly" dose up to .o3 or .05 . So either way I'll be safe. Considering the accuracy of kits available without spending a "lot" It's about the best we can do.
MTBake, Thanks for the reference.

 

[MTBake]

I forgot about the +or - factor so I'll "slowly" dose up to .o3 or .05 . So either way I'll be safe. Considering the accuracy of kits available without spending a "lot" It's about the best we can do.
MYBake, Thanks for the reference.

Test often when you start dosing. I currently dose to .06ppm every 12 hours. My system uses it up quickly. When I test, it's in between doses and I see 30-60ppb with the checker.

 

[Moonfruit777]

@cracker
A little bit late but here is a cool chart which i printed out and put into the checker's box
It lets you convert readings on the fly and shows you the error range
Really handy

http://www.pny.se/aquarium/hanna_ppb_to_ppm_conversion.png

Oh by the way I get a lot of 0 readings on my 125!
No3 is reading 5-10 so Po4 can't really be 0, can it ?
Not to worried since everything does well