Good Titration kit or Hanna checker for phosphate?

ReelRednekReefer · Feb 16, 2015

Just as the title states... Which should I get?

I have the API kit but it only reads down to 0.25ppm.

I recently acid bathed 90lb of nasty dead rock, then bleached and treated with lanthanum chloride twice. Rock looks better than ever! However I never tested above 0ppm with the API kit. I want to allow the rock to purge as much as possible since I have time to let it cure/ cook, purge, clean, cycle, nuke or whatever someone wants to call it. I just wanna start with a clean slate in my new tank.

A seachem kit is $15 and tests down to 0.05ppm. Hanna checker is ~$50 and goes to 0ppm with +\- 0.04 accuracy. Both have varied reviews.

So what's the opinion here? I don't care about the cost. My OCD want the best possible accuracy available....:squigglemouth:

Keithcorals · Feb 16, 2015

Hannah phosphorus checker is what will give to the most accurate low range reading. It will test to 0.001 and has a smaller degree of error but I don't recall what it is.

ReelRednekReefer · Feb 16, 2015

That was my thought but wanted to make sure. Are there specific models for saltwater?

UK_Pete · Feb 17, 2015

That's 0.001 ppm phosphorus which is not the same as phosphate. It works out at roughly 0.003 ppm phosphate.

And owning the other hanna I do not believe that this one, that uses the same reagents and test, is any good to 0.003. The EPA say this type of test (ascorbic acid moly test) is only good to 0.03 phosphate when done in a professional lab, with a proper spectrophotometer able to differentiate colors. My experience with the other hanna is that 0.03 is the best it will do and even then it varies by a least 0.01 if you test the same vials several times.

There are some other threads out on the web with people who have both testers and say they give the same accuracy. Ymmv though!

That said I do like my hanna but I might go back to a quality traditional test as the hanna is expensive per test and quite slow ironically IMO.

choff · Feb 17, 2015

The 736 is the one that is one specifically designed for marine environment.

This is from Hannah:
"Hello, and thank you for your interest in the Hanna checkers! There are some key differences between the two checkers. The HI 713 is designed for most water applications, while the HI 736 is a marine checker, which is designed for use with saline water. The HI 713 gives results in ppm phosphate, and the HI 736 gives results in ppb phosphorus; the HI 736 is therefore more sensitive because it can detect much lower concentrations. Regardless of the checker units, the results can easily be converted to the desired units by multiplying by a correction factor.

To convert from phosphate to phosphorus, divide results by 3.066, and to convert from ppm to ppb, multiply by 1000. To convert from phosphorus to phosphate, multiply results by 3.066, and to convert from ppb to ppm, divide by 1000. In summary, when deciding which checker is right for your application, consider (1) the salinity of the water, and (2) the expected concentration range, remembering to convert units if necessary.

Hanna Instruments

pickupman66 · Feb 17, 2015

I prefer the Phosphate tester because of its flexibility. it allows you to check Fresh water as well as your salty water. This is good if you are diagnosing an issue and want to test your Top of reservoir water.

Randy Holmes-Farley · Feb 17, 2015

Just to be clear, none of the available phosphate kits are titrations.

A titration involves adding a reagent to some endpoint, such as a pH or color change.

Phosphate tests, whether the Hannah or other kit are all photometric (color matching) methods.

ReelRednekReefer · Feb 17, 2015

Ok. Good to know. I sent you a PM. ? about cleaning my rocks.

ReelRednekReefer · Feb 17, 2015

Tried to send a PM but I see that ain't gonna work. I am documenting the use of a process I believe you may have something to do with, or promote or maybe can just tell me what to do next. I believe I saw your name associated with it in some fashion. Please review my progress so far and recommend next step. Heres my thread: https://www.reef2reef.com/forums/member-tanks/191858-reelrednekreefers-90g-build.html