Reviews: aquarium maintenance

Fish & Aquatic Pets

Koller Products Small Aquarium Filter Cartridges 6-Pack, High-Efficiency Replacement for 3–6 Gallon Aquariums, Keeps Water Crystal Clear

A practical, no-frills 6-pack of small replacement cartridges for Koller and Hawkeye power filters. Easy to install, contains activated carbon, and designed for 3–7 gallon setups.

Fish & Aquatic Pets

Tetra Whisper Bio-Bag Large Filter Cartridges for Aquariums, 12 Count, Unassembled, Fits Tetra Whisper Fish Tank Filters 10-30 Gal, 20-40 Gal, PF-20, 30, 40, 60, IQ 20, 30, 45, 60

I tested the Tetra Whisper Bio-Bag Large as a value-minded replacement cartridge for compatible Whisper filters. It is simple, effective, and worth buying if you are okay assembling the bags yourself.

Fish & Aquatic Pets

Tetra Whisper Bio-Bag with Stay Clean, Large Filter Cartridges for Aquariums, 12 Count, Unassembled, Fits Tetra Whisper Fish Tank Filters 10-30 Gal, 20-40 Gal, PF-20, 30, 40, 60, IQ 20, 30, 45, 60

The Tetra Whisper Bio-Bag with Stay Clean is a large, 12-count aquarium filter cartridge pack made for several Tetra Whisper in-tank and external filters. I like the water-clarity performance and easy maintenance, but the packaging and charcoal dust issues are real.