Hydro-Logic Stealth/Small Boy Catalytic Carbon Replacement Filter


SAVE $18.39 (32%)

Improve water quality with the Hydro-Logic Stealth/Small Boy Carbon Filter. This filter works to remove most harsh chemicals/containments that are found in well or hard water. Replacement filter for the Hydro-Logic Small Boy Filter System

  • Granular Activated Catalytic Carbon
  • Reduces: Iron, sulfur, chlorine, and heavy metals.
  • KDF85 media

More Info

Only 4 left in stock




Hydro-Logic Stealth/Small Boy KDF85/Catalytic Carbon Upgrade Filter

KDF/Catalytic Carbon Filters reduce iron, sulfur, chlorine, chloramines and heavy metals. Great for city or well water! Doubles standard green carbon filter. Measures at 10 in x 2.5 in.

KDF85 is the most advanced media that one can use when it comes to filtering water along with pre-treating water before Reverse Osmosis filters. KDF85 not only has incredible chlorine and chloramines removal capabilities but it can also be successfully used for those on well or spring water sources to remove many other contaminants that can cause major problems in your garden. Nutrient lockout can be caused by several factors in water quality. Water high in iron and sulfur can be very common problems that lead to decreased yield and quality. These contaminants can also quickly foul Reverse Osmosis membranes, so pre-treating the water and removing them is crucial to a properly operating filter system. KDF85 replacement filters are available for all Hydro-Logic’s Reverse Osmosis and de-chlorinating filters. Your beneficial micro-organisms will thrive and be at their healthiest population by removing these harmful substances. Your plants will thank you with bountiful harvest and superior quality. Pure water’s not magic, it’s logic!

KDF85 Filter is ideal for well water users with iron and sulfur and city water users with chloramines. KDF85 filters eliminate 95% of harmful chloromines. KDF85 filters last over 6 months, over twice as long as standard carbon filters.


Flush the filter for approximately 5 minutes prior to use. Bacteriostatic qualities do not allow microbes to breed in filter.

Replacement Schedule:

stealthRO: Every 2,000 gallons of filtered water

smallBoy: Every 6,000 gallons of filtered water



Weight 1.5 lbs
Dimensions 3.5 × 3.5 × 10.75 in

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