Red sea PO4 test kit or hanna checker

[jerpa]

The Hanna 736 has an accuracy of plus or minus 5 ppb, so it's margin for error is .03ppm. The resolution is .003ppm.

There have been reports of inconsistencies with the checker as well. I have had consistent and seemingly logical results with mine. Every once in awhile I get an abnormally high reading, but a small piece of food in the test sample can spike it so I usually retested.

 

[Bilk]

I have read the forums about this kit not reading below .08 ppm. I too have the problem. I am reading .08 ppm on RO/DI water. This is a brand new RO/DI filter. I'm reading 0 TDS on the inline meter.
I had some heavy grean algae growth on the tank glass a week ago, so I ran the test and found it at .08. I started up a GFO reactor and havent had any algea on the glass since.
Ive noticed an improvement in the SPS corals since i started up the GFO reactor so i assumed the PO4 test kit was going to show a change. Unfortunatly it still reads .08 ppm.

Since i havent cleaned the glass in a week and its still algae free, I have to assume that my PO4 is pretty low. But it seems there is no way of knowing for sure.
So my question is. Would the hanna checker be any more reliable ? Or should i use the rate of algae growth on the glass as a way of determining my PO4 levels?

I use both. The Hanna always reads higher than the RSP kit. I think the Hanna has more issues with accuracy and more variables that can effect a reading. The Hanna test say fill with 10ml. I've measured out 10ml and used the mark on the vial for tests. The mark is not 10ml as measured with a lab grade graduated cylinder. That packet is a PITA too. Getting all of the regent out is problematic and if your fingers touch in inside of the packet, residue from your fingers can effect the reading I would think.

I use both as a way to determine a trend. I think getting a true number is elusive.

 

[Zedar]

I use both. The Hanna always reads higher than the RSP kit. I think the Hanna has more issues with accuracy and more variables that can effect a reading. The Hanna test say fill with 10ml. I've measured out 10ml and used the mark on the vial for tests. The mark is not 10ml as measured with a lab grade graduated cylinder. That packet is a PITA too. Getting all of the regent out is problematic and if your fingers touch in inside of the packet, residue from your fingers can effect the reading I would think.

I use both as a way to determine a trend. I think getting a true number is elusive.

Thanks for your insight. I think Bertoni said it best. " You could choose to ignore the phosphate reading, for that matter, as long as your animals are okay. "

Use your skills of observation. That seems to be the best advice.

 

[kissman]

I find my 736 always reads the same as my Red Sea Pro kit does. The packet is very easy to use if you cut two sides and create a funnel to pour in the vial. The 10ml is off and I use a syringe to measure my 10ml. Most vials from any company I have seen have been off. All test kits have a +/- accuracy. I have had a few times I did get an abnormal reading. But, I found the same with other kits as well. I find the digital is a lot easier to read than trying to match up colors.

 

[Trevenator]

I was just looking on bulk reef supply for a refill for my Magnesium kit and noticed that they have 4 people that reviewed the Red Sea Phosphate kit also get the .08 readings that we have been getting.

 

[Zedar]

Yeah it looks like its not just a few isolated incidences. I'm heading over my nephews tonight to compare my kit with his. I'll see if his is accurate.

 

[bertoni]

One instance of the Hach test kit was checked against some fancy lab equipment. It worked "well enough for our purposes". Any brand or type of kit can have some problems over time, but the Hach PO-19 seems to have passed some tests very well. Unfortunately, you might be the "lucky" one and get a bad copy.

If the kit is hard on your budget, I think that ignoring phosphate readings is a fine choice if you animals are all doing well.

 

[skuller]

Sorry guys, but this is a normal issue for the Red Sea Pro PO4 test, I had it and below 0.08 it always measured 0.04, even testing RODI water.


It seems the test can't read below 0.08 values.

I contacted Red Sea, they only sent some samples to test, but never changed the test or returned the money. :mad2:



I will never use any other test than HANNA to test Phosphates, it is the most accurate test you can get.

 

[Zedar]

One instance of the Hach test kit was checked against some fancy lab equipment. It worked "well enough for our purposes". Any brand or type of kit can have some problems over time, but the Hach PO-19 seems to have passed some tests very well. Unfortunately, you might be the "lucky" one and get a bad copy.

If the kit is hard on your budget, I think that ignoring phosphate readings is a fine choice if you animals are all doing well.

Thanks again. Ive been an RC member for many years and have always valued the advice of the people here in the chemistry forum.

 

[bertoni]

You're welcome. Good luck! Most of us seem to need it with testing equipment.