How to Properly Clean Your Fish Tank

Keeping your aquarium clean is about more than just crystal-clear water—it’s about creating a healthy, balanced home for your fish and plants. A well-maintained tank supports strong biological filtration, stable water parameters, and happy fish with fewer disease risks.

But cleaning your tank the wrong way can actually cause more harm than good. That’s why it’s important to understand the three key parts of aquarium maintenance: chemical, mechanical, and equipment care. Each plays a different role, and together, they keep your aquatic system thriving.

Chemically

Chemical cleaning in aquariums doesn’t involve scrubbing with harsh cleaners—in fact, most of those can harm your fish.

It’s about maintaining the right water chemistry using safe tools and supplements. Always use a water conditioner (like Fritz Complete Water Conditioner) to neutralize chlorine and chloramine during water changes.

Test your water weekly for ammonia, nitrite, nitrate, and pH using an aquarium test kit. Ammonia and nitrite should be at 0 ppm, and nitrates should stay under 40 ppm for most setups.

If your water has unwanted tannins from driftwood or algae discoloration, chemical filtration media like activated carbon or Purigen can help absorb those impurities. Just remember: chemical tools support your tank’s balance—they don’t replace regular maintenance.

Mechanically

Mechanical cleaning focuses on physically removing waste and buildup to keep your aquarium clean and healthy.

Start by scrubbing algae off the glass using an aquarium-safe scrubber or magnetic glass cleaner. Avoid using kitchen sponges or chemicals—these can leave behind residues harmful to fish.

Be extra careful with metal razor- stye scrapers. I have messed up the silicone sealant on more than one tank that way. It leads to gross unreachable buildup under the broken seals at best, and a busted, leaking tank at worst.

Next, trim or reposition your plants. Removing dead leaves and thinning out overgrown areas improves circulation and reduces decay, which, unsurprisingly, can contribute to cloudy water and poor water quality.

Finally, siphon the gravel or substrate during your weekly partial water change—this step is key. A gravel vacuum removes uneaten food, fish waste, and debris trapped between the substrate without disturbing beneficial bacteria.

Aim to remove 20–30% of the water while cleaning the substrate, especially in high-traffic areas where waste tends to collect. Doing this regularly keeps nutrient levels in check and your tank looking spotless.

Equipment

Your filter, heater, lights, and other gear are the engine of your aquarium, and they need regular care too.

Every 2–4 weeks, rinse filter sponges or floss in used tank water to remove gunk while preserving beneficial bacteria. Avoid cleaning all your media at once—if you’re using multiple layers (mechanical, biological, chemical), clean them on a rotating schedule. Check for debris in your filter’s intake and outflow tubes, which can reduce flow.

For heaters, inspect for calcium buildup and test for consistent temperatures using a thermometer. Airstones and airlines can clog over time—replace or clean them as needed. Wipe down lights, lids, and glass above the waterline to keep everything functioning efficiently and avoid overheating.

A Cleaner Tank, Less Stress for You

Once you understand the why behind each type of tank maintenance, keeping your aquarium clean becomes a routine instead of a chore. Clean tanks don’t just look better—they support better fish health, stronger plant growth, and more stable water parameters.

Best of all, when you clean correctly and consistently, you won’t need to scramble with emergency fixes or expensive treatments later on. Keep your system balanced from the inside out, and your tank will reward you with a thriving underwater world that’s easy to enjoy.