Air pump versus a powerhead for surface agitation
An air pump and a powerhead can both improve surface movement, but they solve different aquarium problems. Choose an air pump for gentle…
Sizing & comparisons
Help matching aquarium filters and pumps to tank size, bioload and noise tolerance.
Comparisons
Green water: more filtration or a UV unit
Green water is usually caused by free-floating algae, so a UV clarifier is often faster than simply adding more filter capacity. Filtration…
HOB versus canister filter
HOB filters are simpler and easier to maintain, while canister filters offer more media capacity and flexible filtration. Choose based on…
Internal filter versus hang-on-back
Internal filters are compact and simple, while hang-on-back filters usually offer easier media access and more flexible filtration. The…
Marine sump versus a hang-on-back on a FOWLR tank
A sump gives a FOWLR tank more equipment space, water volume, and expansion potential, while a hang-on-back filter is simpler, cheaper, and…
Matten filter instead of a canister on a shrimp tank
A matten filter can be an excellent canister alternative for shrimp tanks when you value gentle flow, large biological filtration capacity,…
Overflow box with a return pump versus a canister
An overflow box and return pump provide a flexible sump-based filtration system, while a canister is simpler to install and usually better…
Powerhead plus sponge versus a cheap HOB
A powerhead plus sponge offers flexible flow and gentle, highly reusable filtration, while a cheap HOB is usually simpler and more compact.…
Sponge Filter Versus HOB for a Shrimp Tank
Sponge filters are usually the safer, gentler choice for shrimp and babies, while HOB filters offer stronger mechanical filtration and…
USB Air Pump Versus Wall Air Pump: Which Is Better?
USB air pumps are convenient and portable, while wall-powered pumps are usually the better choice for continuous everyday aeration. The…
DIY hang-on sponge versus buying a HOB
A DIY hang-on sponge can provide gentle, simple filtration if it is built around a reliable airlift. A ready-made HOB is usually easier to…
Protein skimmer is not a freshwater filter substitute
A protein skimmer can remove some dissolved organic waste, but it does not provide the dependable mechanical and biological filtration most…
Undergravel Plate as an Old Alternative to a HOB
An undergravel filter plate can still be a practical alternative to a hang-on-back filter when the tank has suitable gravel and you’re…
Water Changes Instead of a Stronger Filter
Water changes can control nitrate and remove dissolved waste, but they cannot replace adequate biological filtration. Use water tests and…
Flow & Size
Can two HOBs share one tank
Two HOB filters can safely run on one aquarium when the tank rim supports both units and the combined flow is suitable for the fish. The…
How much filter flow a tank needs
Use tank turnover as a starting point, then adjust for filter media, hose restrictions, fish waste, and species that prefer calmer or…
One large filter versus two smaller filters
One large filter is usually simpler and more space-efficient, while two smaller filters can improve circulation, provide backup, and divide…
What size filter for a 10 gallon tank
For most 10-gallon aquariums, choose a filter rated for roughly 10 to 20 gallons with a usable flow of about 40 to 60 gallons per hour.…
What Size Filter for a 55 Gallon Tank?
A 55-gallon aquarium typically needs a filter rated for at least 55 gallons, with practical flow around 220–330 gallons per hour for many…
GPH ratings versus real head loss in a canister
A canister filter’s advertised GPH is not necessarily the flow you’ll get on your aquarium. Compare ratings carefully, account for…
Tank turnover rate for goldfish versus community fish
Goldfish generally need more filtration capacity than many community fish because they produce substantial waste. Use turnover as a…
What GPH Means on an Aquarium Filter
GPH means gallons per hour: the amount of water a filter is rated to move. Use it as a starting point, not a complete measure of filtration…
Media
Foam versus ceramic bio media
Foam and ceramic media do different jobs in an aquarium filter. Learn which provides mechanical filtration, which supports beneficial…
Seachem Matrix Versus Ceramic Rings: Which Filter Media Is Better?
Seachem Matrix and ceramic rings both support beneficial bacteria, but their structure and best uses differ. Here is how to choose between…