Sprite Slim-Line 2 review

Both facts are true, and that is the lesson

A reader could reasonably feel that a certified filter measuring 42 percent is a scandal. It is not, and working out why is the single most useful thing on this page.

NSF/ANSI 177 requires a filter to reduce a 2.0 mg/L free available chlorine challenge by at least 50 percent throughout its rated service life, at the manufacturer's stated flow rate, under controlled laboratory conditions. That is a floor, tested against a defined challenge. It is not a prediction about a specific home supply, at a specific cartridge age, at a specific flow rate, with a specific incoming chlorine concentration.

WaterFilterGuru measured 2.70 PPM going in and 1.54 PPM coming out on their own water. That is a different test, on a different supply, with a higher influent than the standard's challenge. Both numbers are real and they are answering different questions.

The media, and the branding of it

Sprite brands its media Chlorgon, which is KDF combined with calcium sulfite. That is the same pairing Jolie uses and the same pairing Kitsch uses, at a very different price. The chemistry is not the variable that explains the price gap in this category.

What Sprite adds is the certification and a low-profile body — the original Slim-Line series sits at roughly an inch and a half, which is the smallest footprint here and matters in a tight shower. What it does not add is a premium housing; the independent reviewer described the plastic as feeling flimsier than most of the filters tested alongside it.

The flow rate, measured

Claimed 1.8 GPM, measured 1.65. That is a small shortfall and it is exactly the kind of thing that only shows up when somebody puts a bucket under it. It is also within the range you would expect from a filter with a cartridge that has seen some use, and it is still above the 1 gpm at 80 psi that the certification requires.

And hardness, for completeness

The same independent testing measured hardness going in at 128.19 PPM, or 7.49 grains per gallon, and coming out pretty much the same. Sprite makes no softening claim, so this is not a contradiction — it is another data point in the category-wide finding that no shower filter softens water.

Who it is for

• Clearance is tight and you need the smallest inline body available.
• You want a certification, and you want to keep your existing shower head.
• You want the cheapest route to a traceable NSF/ANSI 177 listing on an inline unit.

Who should skip it

• Maximum chlorine reduction is what you are buying. On the one independent measurement available, this was the lowest in its set — the Weddell Duo was the highest.
• You want a solid-feeling housing. The brass Slim-Line variant exists for that reason.
• You are on chloraminated water. KDF and calcium sulfite is not the media, and the certification does not cover it.