Hanna InstrumentsHI736 Phosphorus Ultra Low Range Checker HC for Saltwater Aquariums

I have Been keeping Reef Tanks for 31 Years and these Hanna Test kits are the Best ones I have ever used. I moved from the Red Sea pro models that I had to Hanna and I will never look back unless Hanna does not have a kit for what I need. I have used Red Sea, Salifert, API an ELOS and while I have to admire the Bang for the buck with API kits, but the accuracy is just not good enough for serious tanks.Using the ULR Phosphorus versus the Phosphate unit was a tough choice, the Phosphorus reading does require a little math to convert it into Phosphate but the beauty is that the reading is about 4 times more accurate than using the Phosphate unit and that really shows up when your trying to read very small Phosphate amounts.With the Hanna kits there are a few tricks to getting accurate results, I will be doing a you tube video on that for people to see, needless to say if you dip them in a Tank to fill the vials, after you get the level right and seal the vial, make sure to rinse the outside off and your hands with fresh water and then dry it with a paper cloth and give it a final polish with a reading glasses cleaning cloth. If you do this and use them properly you get consistent accurate results and the real beauty is that you don't have to look at anymore color charts and the test are so much easier to perform than the old school stuff. I can do 4 different tests in under 10 minutes and have good results that are repeatable and match what I expect after dosing.

I find this device to be both consistent and reliable(I actually test against my red sea pro test kit to confirm it's reagent viability). It only comes with reagents for 6 tests and the test is so easy, that you should just include another set of reagents in your order upon purchase of the meter.The one thing that I find a bit annoying,is that you have to work quickly with the reagent and sample at C2 stage or the meter times itself out. So, just being prepared by cutting the dry reagent and creating a pocket for that, will solve this for you.It works quickly and accurately over and over.

I left my previous review from a year and a half ago so you can compare. After using this for a year and a half and improving my technique, I am completely satisfied with it. I use a Red Sea test kit, which is hard to read (trying to match colors, especially at the lower levels), for comparison. Hanna is as accurate as you are going to get with a hobby grade instrument (and price). My problem was experience using it and probably that my phosphorous levels were just a lot higher than I thought possible at the time and the ULR is intended for very low readings. Also, I think I was just too OCD in my expectations. Phosphates are now controlled and phosphates translate to 0 - .02 consistently. Best advice I have is use a bottle brush on the vials before and after each test, to insure cleanliness and put the vial in the checker the same way each time. I remember this by always facing the 10ml numbers toward the front. This solved the consistency problem completely for me. Also if you have an Apex controller, Fusion makes the conversion from phosphorous to phasphate for you. So easy with no confusion.My problem with this checker is that the accuracy is always suspect. I am sure it is a problem with the way the reagent is managed when doing the test, but I have done three tests in a row with the same tank water and gotten a range of 141 to 86 to 41 ppb. Which one is right? Who knows. This is a consistent problem. All test kits have a similar problem and the reason it is noticeable with this checker is that it can give you a specific reading down to 0 ppb when other test kits read 0 or .26 or higher reading from color cards, which I feel is not accurate at all. So this is much better, but still frustrating and leaves you guessing.

Great product and easy to use

The battery cover is a pain to remove.My other Hanna test kits came with 25 tests worth of chemicals, this one only comes with a few for some reason.If you're having trouble with the timer, then just fill the second cuvette with your test water and swap the two during the test instead of trying to do everything with one. The small difference between the two will be negligible for aquarium use and you can repeat the test several times without using more reagent.

Ignore the grumblers, its a fast and very accurate device. When testing use both vials, one for the sample and one for the reagent and sample. Mix the reagent first then start the test. Less stress and having done it both ways several times it seems to make no difference at all. Be sure the vials are clean before inserting them into the tester as fingerprint, salt, etch will screw up the accuracy.

As advertised,best ULR phosphate test kit

Easy to use. Serves the purpose well