I don't have the problem other users seem to have and matches Hanna ULR closely By jmfugett on 5/7/2017
jmfugett would recommend this product to a friend
I use the Hanna ULR and this kit to check PO4. I started with the Hanna and was frustrated because the test-retest reliability is very poor for me and I end up taking three readings and averaging. The Red Sea is actually easier to test with fewer steps. The color wheel at the low end is very tricky to discriminate the colors, but with some practice works well. I am still trying to find the correct lighting for accurate color reading. When tested with the Hanna the readings are almost identical. The Red Sea does not distinguish measurements as finely as the Hanna as the color variations double the readings with every change in hue (e.g. .0, .02,.04,.08,.16,.36,.64). If my phosphate was higher this would be frustrating to me, but at the low end, between .0 and .08 I don't think it is a big deal. An example of how the two kits relate to each other, tonight the Hanna (tested 2 times) read 0 and .01, the Red Sea was consistent at somewhere between 0 - .02, with great difficulty deciding between the two, so probably .01? At any rate, I have never gotten a reading as high as .08, so I don't know why others are having a problem with that. For me, I am very happy to have this kit and use it regularly.
I wish I could give it a .08 star By Ant on 12/8/2016
Ant wouldn't recommend this product to a friend
Same as the other users I cannot get this kit to read below .08. At the time I tested (and retested and retested and retested) I was running GFO and growing macro so I decided to pick up a Salifert kit and a Hanna checker just to be sure. Of course both pulled "0" readings. I usually love Red Sea stuff, but this kit is a big fat miss.
great concept, indiscernible color matching By Join the Revolution on 3/29/2015
Join the Revolution wouldn't recommend this product to a friend
I should of wrote a review back in 2012 when I bought this test kit but i did not. Long story short, it's really difficult to tell the color wheel from the sample-that itself, is unacceptable for me. Also, I would not mind if the test kit used so much comparative samples to accurately determine the correct end result, unfortunately, this test kit is a time waster and a wallet sink. Gen 1&2 are a total fail.
Don't waste your money, get the Hanna kit instead By Phil on 11/12/2014
Phil wouldn't recommend this product to a friend
I've used this weekly for the last 3 month and it reads .08 every time. I know for a fact my water is not more than .04. If anything I have a difficult time to maintain .02-.04 for sps coloration because of the reactors I'm using. Garbage test kit.
Good Product By Nick on 6/7/2013
Nick would recommend this product to a friend
Some of the older kits were sold with a bad color wheel. This has since been corrected. Very easy kit to use; though it can be difficult to tell the difference between the colors at the lowest of PO4 levels.
Will not read lower than .08 By TrevorJohnson on 4/17/2013
TrevorJohnson wouldn't recommend this product to a friend
Every thing I have tested all read .08 .
My tank water- Fresh made salt water- Natural seawater- 0 tds rodi water.
All test at .08 and I have had 6 other people run the tests and they all get .08 also
Inaccurate By Matt on 1/13/2013
Matt wouldn't recommend this product to a friend
Like others on here have mentioned, this test kit is not accurate. I obtain readings of .08 to .16 when it should be reading zero like on freshly made saltwater, RODIwater, and the water coming out of my gfo reactor (fresh gfo just installed before taking the reading).
always 0.08 By ecfarr on 12/30/2012
ecfarr wouldn't recommend this product to a friend
I bought this kit. I always got a reading of 0.08 on my display tank, gfo reactor output, and my r/o output with brand new filters.
I told my lfs who communicated with red sea. They sent me a new set of reagents a and b. Guess what. EVERYTHING READS 0.08 AGAIN. Red Sea has bad quality control. Never will buy a red seak kit again.
always get 0.08, have issue with this test kit By Jason on 10/4/2012
Jason wouldn't recommend this product to a friend
I have tried using this test kit, but no matter how I test it, and when I test it, I always get a 0.08. Then I found out there's an issue with this test kit from forums.
best po4 kit By Joey on 9/22/2012
Joey would recommend this product to a friend
a lot easier to read than other kits out there and results match the colorometer I bought later.