Having good flow in the tank that sweeps debris towards filter intake keeps the tank cleaner for longer. Overall tank cleanliness is one of the fundamentals for an algae free tank. In new setups and through periods of flux, planted tanks can create a lot of organic debris even with no livestock. A filter is thus useful as a collection point for free floating organic detritus. As a planted tank matures, it creates a mini ecosystem that digests livestock waste well - matured planted tanks can often run well without additional filtration if stocking levels are light. However, having a filter as a backup is a still good idea.
6 THINGS I LOOK FOR
strong + silent flow
For many planted tanks, the filter functions as the main source of water flow. In a planted tank, good flow (5X to 10X turnover of tank volume) is necessary for circulation of O2/CO2 and for delivering nutrients to plants. Spending on a filter with good flow negates the need for extra pumps in the tank.
This enables the starting of the filter without the need to manually start the downward flow of water in the filter intake pipes. (i.e. sucking on the water hoses). Enables easier maintenance work and setup.
Easy accessibility is the best way to encourage regular maintenance and tank cleanliness. And nothing helps this more than a pre-filter compartment that can be cleaned without needing to take the filter apart. Planted tanks produce a lot of debris - that should be removed regularly.
Less equipment in the tank maximizes space for aquascaping. Being in the center of flow ensures that heated water is distributed evenly throughout the tank.
quick release valves
This enables the filter to be serviced without fumbling with the water hoses. Quick release shut-off valves allows one to remove the filter from the water pipes that run into the tank instantly without mess/dripping water.
Filters last a very long time if they are built of quality materials. Poor quality models have higher risk of leaking and breakdown.
Example of an all-in-one filter
This is my current go-to filter for all my larger tanks. It is made of good quality materials and have all the 5 features listed above:
- Heater compartment (one less item in the tank)
- Quick release taps (disconnect hoses from filter easily)
- Removable pre-filter (allows servicing of filter without taking it apart)
- Silent, strong flow
- Working priming mechanism (easy to start flow into filter during setup)
removable pre-filter compartment
The biggest difference between this filter and other models on the market is that it has a pre-filter compartment that can be removed without taking the rest of the filter apart. As planted tanks produce a lot of debris, it makes filter maintenance much easier to be able to clear the pre-filter regularly without actually take the rest of the filter apart. Convenience encourages good maintenance habits, and clearing away organic waste regularly directly impacts algae presence in the tank.
*Pre-filter compartment can only be removed when right side quick release taps are locked, stopping water flow from tank.
Coarse organic debris is captured in pre-filter before tank water enters the main filter chambers.
quick release taps & priming
It has a quick release lever that locks off flow of water and allows separation of the hoses and filter to allow easy removal of the filter without mess of water spilling. Some other brands sell quick release taps separately at increased cost, but this feature here comes inbuilt.
On top of the pre-filter sits the priming button. Pushing this down when the filter is fully setup (with the inlets and outlets inside the tank) draws water down from the tank into the filter. This allows starting up the filter easily without sucking on hoses to start the water flowing.
The Oase Biomaster filter comes with a good mix of Bio-media, coarse filter foam and fine filter foam. The filter media is easily changed to your personalized choices.
SOME CHOICES I WOULD AVOID
Hang on filters for planted aquarium function well enough for many fish-only tanks. However, many of them produce an unfavourable flow pattern that changes as the water level in the tank changes. Many of them are designed with a downward pointing rather than horizontal outflow direction, which I find less ideal. I find them usable on low tech tanks, but hard to manage on CO2 injected tanks, especially ones that depend on flow to distribute CO2 mist.
sponge filters powered by bubble lifts
For sponge filter in planted tank, the bubble lifts off gas quite a bit of CO2. Also, unless there is supplementary flow through additional pumps, I find that most sponge filters don't give optimal flow patterns in a tank. Such filters takes up valuable space in the tank and are hard to hide.