Standard Filter OB03: 40-Gallon Chlorine Reduction
The Brita Standard filter (OB03, also sold as Brita OB03 White) is compatible with all Ultramax dispensers and most Brita pitchers. Certified under NSF/ANSI Standard 42 for chlorine taste and odor reduction. Rated for 40 gallons, which equals approximately 150 liters or 2 months of daily use for a 2-person household. Replace at the 40-gallon mark regardless of water clarity -- the carbon media is exhausted at this point and no longer reduces chlorine effectively. Price is $7-9 per cartridge at retail.
Longlast Filter OB06: 120-Gallon Lead and Chlorine Reduction
The Brita Longlast filter (OB06) is certified under both NSF/ANSI Standard 42 (chlorine taste and odor) and NSF/ANSI Standard 53 (lead reduction). Lead reduction claim: greater than 99% reduction of lead at the concentration tested under NSF 53 protocol. Rated for 120 gallons -- 3 times the capacity of the Standard filter. Compatible with the Ultramax 27-cup dispenser and the Brita Grand pitcher. Not compatible with the Stream pitcher or Brita faucet mount systems -- confirm compatibility before ordering. Price is $16-18 per cartridge.
Stream Filter RF-100: Pour-Through Filtration
The Brita Stream filter (RF-100) is specific to the Brita Stream pitcher and is not interchangeable with OB03 or OB06. It is certified under NSF 42 for chlorine reduction only -- no NSF 53 lead certification. Rated for 40 gallons. The RF-100 installs in the pour spout, not the reservoir, so filtration occurs on the way out of the pitcher rather than on the way in. No priming is required. Replace every 40 gallons or 2 months.
Ultramax Spigot O-Ring Replacement
The Brita Ultramax spigot (tap) uses a small O-ring to seal the valve against the dispenser body. If the spigot develops a slow drip at the base, the O-ring has deformed. Brita includes a replacement O-ring in the original packaging but does not sell it as a standalone part. A standard 3/16-inch ID by 5/16-inch OD nitrile O-ring from a hardware store is the correct replacement. Remove the spigot by pulling outward firmly, swap the O-ring, and press the spigot back until it clicks into the housing. This repair takes under 5 minutes.
Hub Cartridge Replacement
The Brita Hub under-sink filter cartridge (part BBSF) is specific to the Hub system and snaps in without tools. NSF 42 and NSF 53 certified. Rated for 6 months or 750 gallons. Replacement procedure: turn off supply at the saddle valve, press the cartridge release button on the housing, pull the old cartridge out, insert the new cartridge until it clicks, restore supply, and flush 2 gallons through the Hub faucet before drinking. The Hub housing has a built-in LED that indicates when the cartridge requires replacement.