Filtration is where most people either get it right or completely mess up their tank. You can have the best setup, nicest fish, perfect decor… but if your filter isn’t right, nothing else matters.
First thing, don’t cheap out on filtration. I see this all the time — people buy a decent tank, then throw on a basic filter that can barely handle the load. That’s when you get cloudy water, bad smells, and constant issues.
The Main Filter Types
There are a few main types of filters, and each has its place.
Internal filters are the most common starter option. Brands like Aqua One and Fluval make decent ones. They’re easy to set up and fine for small tanks, but they clog quickly and don’t handle heavy bioloads well. Good for beginners but you’ll outgrow them.
Hang-on-back (HOB) filters are a step up. Seachem (like their Tidal range) and AquaClear are solid options. These give better filtration and are easier to maintain. The downside — they’re still limited for bigger or heavily stocked tanks, and you’ll need to stay on top of cleaning.
Canister filters are where things get serious. Brands like Eheim, Fluval, and Oase are some of the best. These sit outside the tank, hold more media, and give you proper filtration. Water stays clearer, parameters stay stable, and maintenance is less frequent. The only downside is cost and setup — they’re more expensive and take a bit more effort to install, but they’re worth it.
Always Oversize Your Filter
Here’s the key — your filter should always be stronger than you think you need. Don’t match it exactly to your tank size. Oversize it, especially if you’ve got messy fish like goldfish or cichlids.
It’s Not Just the Filter — It’s What’s Inside
It’s not just about the filter — it’s what’s inside it. Good filtration media makes a massive difference. You want a mix of:
- Mechanical (sponges) — catches physical debris
- Biological (ceramic rings, bio media) — houses the beneficial bacteria that break down waste
- Chemical (carbon if needed) — removes odours and certain toxins
This is what keeps your ammonia and nitrites under control.
Don’t Over-Clean Your Filter
One more thing I see a lot — people cleaning filters too aggressively. If you wash everything under tap water, you’re killing the good bacteria. Always rinse media in tank water, not fresh tap water.
The Bottom Line
A strong, reliable filter makes your life easy. Your water stays clean, your fish stay healthy, and you’re not constantly fixing problems.
If you’re in Melbourne and not sure what filter suits your tank, Aquatics by Ash can help you choose the right setup, install it properly, and keep it running the way it should — no guesswork, no wasted money.