NYOS® Phosphate Reefer Test Kit for Saltwater Aquariums - Ultra-Sensitive 0.025-1.00 mg/l PO4-50 Tests - Lab Grade - Glass Vials

CAVEAT EMPTOR! I ordered a NYOS phosphate test kit, but what arrived was an AquaForest kit. This is a cheaper kit in both senses. It normally sells for a couple of dollars less than NYOS, uses a crystallized reagent that tends to clump making it hard to get the tiny amounts correct, has a cheap plastic test vial instead of glass and the colors on the color chart are virtually inseparable even if you manage to find a readable bit of blue in the vial. The optical characteristics of the vial cause shadows and bright spots on the bottom that make comparison with the color chart impossible no matter what light you try to read it in. Don't waste your money; make certain you get the NYOS kit (assuming that's what you ordered).

Very easy to read compared to the API test kit except the low reading only goes down to 0 and is only read in whole numbers. Got those needed a reading lower than 0 you need a different kit.

Made of quality elements. Read and follow instructions carefully inside the manual and not the one at the back page. The results are hard to distinguish below 0.1 so I used a magnifying lens under a bright light. I'm guessing it's because phosphate levels below 0.1 are insignificant already. My conclusion is that the closer to white1/white2, the better.

Two nice, solid vials but only one of the two came with a screw-on cap. Not certain what that is all about but it opens the door for contamination of one vial after filling with tank water. The color comparison chart is printed on a piece of large, cumbersome, coated paper. Mine got wet on first use. Otherwise, comparable to other hi-res kits I've used. Seems accurate when tested against both a Hanna Checker and the Red Sea kits.

Much better than API. The api test only goes to 0.25 and 0. Algae can still become a problem between that range. This is a really fast test. My only complaint is that the very light colors are indistinguishable.

Best phosphate kit I’ve ever used

Good product

Easy to use, works well!

Ottimo test, affidabile con una buona scala colorometrica e facilità di confronto attraverso le due boccette