Mechanical media traps particles
Foam, floss and pads capture debris. Coarse collection and fine polishing are different jobs; fine pads can restrict flow as they load. Choose the permitted grade and dimensions and observe installed flow alongside the service instructions.
A cartridge may combine particle-catching material with carbon. Replacing it can remove several stages together. Read the exact filter’s included-media list before ordering supplies.
Biological media supports waste-processing bacteria
Foam and biological media provide surfaces for organisms that process waste. Newly purchased media is not a mature biofilter. See the what to do before adding fish.
Do not routinely discard all established media to make it look new. Use the model’s cleaning-water and replacement instructions, preserving its biological stage. A sponge can perform mechanical and biological jobs together.
Chemical media has a specific job
Activated carbon and other chemical media act on particular dissolved substances. They are not interchangeable and do not replace particle collection or a functioning biofilter. Choose for an identified problem and follow the medium’s label for preparation, quantity and service life.
Do not fill every empty basket space arbitrarily: packing changes the water path. Carbon use during treatment belongs to the treatment instructions, not a universal rule here.
Follow this filter’s water path
Canisters, HOB baskets and cartridge filters route water differently. For the Fluval 107 and 307, follow the 07 Series foam-screen and basket arrangement. For Tidal 35, use its own basket instructions.
- Record exact filter and replacement-medium identities.
- Find where water enters each stage.
- Confirm the bag, basket or cartridge required.
- Keep preparation and cleaning rules with the supplies.
Check the filter after restarting it
Use the filter maintenance sequence for isolation, opening and restart. Record what changed and the resulting flow. Continued leaks, noise or low flow require the exact model’s troubleshooting checks; buying more media is not a diagnosis.