Red Sea Fish Pharm ARE21425 Saltwater Phosphate Pro Test Kit for Aquarium, 100 Tests
$57.99
Price: $57.99
(as of Oct 14, 2025 17:58:09 UTC – Details)
Phosphate Pro is a high Definition (0. 02ppm) analytical comparator test kit (100 tests) – incl. professional colorimetric comparator.
Is Discontinued By Manufacturer : No
Product Dimensions : 5.12 x 5.51 x 3.15 inches; 14.39 ounces
Item model number : 306017
Date First Available : December 10, 2010
Manufacturer : TopDawg Pet Supply
ASIN : B004FUG848
Best Sellers Rank: #116,317 in Pet Supplies (See Top 100 in Pet Supplies) #168 in Aquarium Test Kits
Customer Reviews: 4.1 4.1 out of 5 stars 81 ratings var dpAcrHasRegisteredArcLinkClickAction; P.when(‘A’, ‘ready’).execute(function(A) { if (dpAcrHasRegisteredArcLinkClickAction !== true) { dpAcrHasRegisteredArcLinkClickAction = true; A.declarative( ‘acrLink-click-metrics’, ‘click’, { “allowLinkDefault”: true }, function (event) { if (window.ue) { ue.count(“acrLinkClickCount”, (ue.count(“acrLinkClickCount”) || 0) + 1); } } ); } }); P.when(‘A’, ‘cf’).execute(function(A) { A.declarative(‘acrStarsLink-click-metrics’, ‘click’, { “allowLinkDefault” : true }, function(event){ if(window.ue) { ue.count(“acrStarsLinkWithPopoverClickCount”, (ue.count(“acrStarsLinkWithPopoverClickCount”) || 0) + 1); } }); });
Phosphate pro test kit is an advanced colorimetric test with comparator
Measuring the level of phosphate in reef aquarium to an exceptionally high resolution of 0. 014 ppm P-PO4
This test kit, when used in conjunction with the nitrate pro test kit, enables accurate dosing of NO3: PO4-X (biological nitrate and phosphate reducer)
This kit includes a durable, chemical resistant plastic case, analytical grade glass vials
Includes material for up to 100 tests
Customers say
Customers find the test kit to be of excellent quality and very easy to use. The color accuracy receives mixed feedback, with several customers noting that the color chart is hard to read.
8 reviews for Red Sea Fish Pharm ARE21425 Saltwater Phosphate Pro Test Kit for Aquarium, 100 Tests
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Julie –
Excellent product
Excellent product. I had never used a kit like this before so it took a couple uses for me to get the hang of it but now it’s easy to use.
ColinP –
Five Stars
Excellent test kit from the industry standard – Red Sea.
Bearfilm1 –
Red Sea Kits are the best!
Color chart is very hard to read since the colors are so close but then again most test kits have the same issue. Other than that its a very nice Pro Kit and I use it often.
Jo P. –
Red Sea makes amazing products. I had API test kits
If there was a 6th star it would get that. Red Sea makes amazing products. I had API test kits. Those are now gone. I will never test my water any other way then with Red Sea.
amnesiac –
Skip this kit, pick up the Salifert
Have to say I’m very disappointed with this test set. For 2 weeks I was showing .08ppm on a system that had carbon dosing and running GFO. Because of Red Sea’s reputation I looked at everything else before I even considered that my test kit might be bad. Sure enough when I explained my situation to my local shop I was told to try another kit. Then when I did the research I found that this is a known issue with the Red Sea PO4 kit. Any level of PO4 under .08 will read .08 every time. Picked up a Salifert test kit and also pulled out my left over API test kit and both showed 0ppm. Just so you know I LOVE LOVE LOVE LOVE Red Sea stuff. This kit is the first dud I’ve experienced from them. I’m sure sooner or later they’ll get it figured out, but until then, do yourself a favor and pick up the Salifert PO4 test kit.
Eric Shavi –
Five Stars
Easy to perform. Easy to interpret.
Amber –
100 tests but expires Oct 2023
I like Red Sea test kits. They are 2nd to Hanna digital tests imo. But itâs really disappointing when you order this 100 tests PO4 kit online and it expires in October this year?! Even if you test weekly itâs only 52 weeks in a year. Not worth it to return and repurchase elsewhere but I know I wonât be ordering it online again. They should try to make sure it has at least 2-years left before expiring when selecting these for online customers. Iâll stick to my LFS from now on even if it costs a little more.
Amazon Customer –
Product is great, very easy to use and to identify colors
Product is great, very easy to use and to identify colors. Other products I’ve used to test phosphate are very tough to read the colors and identify how much phosphate is in the water. The reason I give this three stars is the packaging from both red sea and amazon is not done very well. The bottles could be packed tighter in the red sea container and the amazon box could also be packed tighter with more paper. When I received my product their was some liquid in the red sea container (not much) but enough to pretty much ruin the color disk that you use to identify the color corresponding to ppm value. It is still useable but very hard to read colors.