Salifert phosphate test kit accuracy

[Spitty]

Just curious if anyone has had any issues with the Salifert Phosphate test kit accuracy lately? My tank has been running for 1 year+ and during that time I have tested PO4 with the Salifert kit. PO4 has never been detected. So I increased feeding, took off socks, skimmed only at night, etc, trying to raise nutrients. Still PO4 was undetected with the Salifert kit. I started seeing some unwanted algaes growing in my display despite a ball of chaeto in my sump the size of a basketball. So I purchased a Hanna PO4 ulr checker and to my surprise PO4 read .23 ppm! The Salifert kit reads 0.Wondering if anyone else has had issues with Salifert Po4 kit? Maybe my kit is bunk?

 

[Snoopy 67]

It is very hard for me to distinguish the low ranges so I use a Milwaukee photometer.

 

[Spitty]

I agree the colors are difficult to distinguish, what I don’t get is why the test kit doesn’t produce any color. Maybe just a tiny hint of blue definitely <0.03 ppm according to their chart. Hanna Checker.23 ppm.

 

[Snoopy 67]

Not sensitive enough wold be my guess.

 

[Spitty]

Well I guess the lesson learned here is a guy should not rely on a single test kit. I will never use Salifert to test po4 again. Can anyone recommend a good po4 test kit? I do have a Hanna but would like to try another to check the Hanna.

 

[maroun.c]

U can check it against an ICP which would be the best. Hanna tests very close to ICP for me.

 

[Spitty]

That is a great idea. I’ve never tried an ICP. Would you recommend a certain company?

 

[SeaDweller]

I’d say +/-0.10. My friend registers 0.00 on his salifert and we know that’s not the case. I register 0.10 on mine, and I’m pretty sure mine is probably 0.15+