Hanna Instruments HI736 Phosphorus Ultra Low Range Checker HC for Saltwater Aquariums

As advertised,best ULR phosphate test kit

Easy to use. Serves the purpose well

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 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.

This test kit is accurate however it has many flaws. It is unnecessarily very frustrating at times. The thing is that it automatically turns off after a period of time which ends up wasting packets of reagents (which aren't that cheap when you're using lots of them). Let me explain:First you have to put a vial filled with tank water in the tester and press the button to calibrate. After that you have about 3 mins to dump all the reagent out of its tiny package through the tiny neck of the vial. If you spill some you have to open a new packet, 1 way to waste a packet. Then, if it takes too long to get the stuff out of the packet and get it all dissolved, which takes more than half of the 3 minutes you get, the tester automatically shuts off and since your water sample has reagent in it and the test has to be re calibrated, 2 ways to waste a packet. Then after that you must press AND HOLD the button. If you do not hold, it gives you an instant reading which will not be accurate, 3 ways to waste a packet of reagent. i believe this is meant to skip the timer in case you've messed up you don't have to wait through it (waste the packets faster). In any case, assuming you've done your job well and completed these somewhat tricky steps perfectly, you have a 3 minute timer to wait through before the device displays the correct reading for one minute. If you are distracted during that time and miss that reading for whatever reason, that makes 4 opportunities to waste packets.This is all unnecessary to me. Why does it have to have packets? Why not just a jar of reagent dust and a spoon? like every other test kit i've ever used that had dry reagent. I feel the packets are wasteful. Why does it have to turn off automatically? Just getting rid of that can help things because you aren't nearly as likely to spill the packet if you aren't rushed. Why make it so that you have to long press the button to start the timer? I would have had a normal button press to start and a long press to skip. why not have it display its prior reading when you turn it on, just in case you missed it? or how about a beep when its ready? That seems like an easy feature to implement or maybe just make it time out after 3 minutes at the end or not at all. ive gone through WAY MORE $ in reagent because of this battery saving 'feature' than battery costs, just saying.Furthermore, a random bubble on the glass, a fingerprint, a bit of undissolved reagent in an unlucky spot can all throw off your test results. After doing countless tests with this i realized you can get very accurate readings but not 100% consistently. I'll get like 23, 56, 27,42, and then an occasional 158 or something all doing tests on the same body of water one after another. Sometimes the reagent dissolves very quickly for whatever reason but i noticed that those times the tests are usually one of the lower numbers.All in all this item is still the best option for reading phosphate levels but be aware of the quirks and buy one of those 25 packs of reagents right of the bat because im pretty sure it only came with a few when i bought it and if i remember correctly i used them all the first day because several were wasted.

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.