How to Clean a Freshwater Tank

A healthy aquarium not only has clear water but also water that is clean and safe at a chemical level. Maintain a strict cleaning regimen and diligently test your aquarium water to ensure healthy, happy fish and an attractive tank. The tank should be inspected regularly for sick and dead fish and any dying plants should be removed. Cleaning and water changing should be done on a weekly basis, although more specialized tanks (such as heavily planted tanks and goldfish tanks) may require an alternative maintenance routine. Remember that all equipment must be clean, free of any chemical residues and dedicated for aquarium use.

Things You'll Need

2 buckets
Jug
All-in-one gravel cleaner and siphon
Ammonia testing kit
Nitrite testing kit
Nitrate testing kit
Soft sponge
Water conditioner
Soft brush
Scissors

Instructions

Preparation
- 1
  Test your aquarium water for ammonia, nitrite and nitrate. Record the results.
- 2
  Turn off all electrical equipment on the tank and allow heaters to cool for 20 minutes.
- 3
  Fill one of the buckets with fresh water. Add water conditioner to the bucket in accordance with the manufacturer's instructions. Mix well.
Decor
- 4
  Gently remove any non-living decorations that are covered in algae and place in the bucket of treated water. Use the sponge and brush to gently clean the decorations, taking care not to damage any paint or delicate parts.
- 5
  Once clean, place decorations onto a clean surface and empty the bucket.
- 6
  Use the scissors to remove any dying or algae-covered leaves from the plants. Remove any fallen leaves, dying plants or unwanted seedlings.
- 7
  Use the small brush to gently clean any residual algae off plants. Use the sponge to remove any algae from the internal surfaces in the tank such as glass, filter and heater.
Water Change
- 8
  Use the gravel cleaner and siphon to remove aquarium water into one of the buckets. Gently move the siphon over the substrate to suck up any debris such as fish feces and uneaten food. Avoid disturbing the roots of plants. Always pay attention as fish can be very curious and get sucked up.
- 9
  Stop the siphon once the bucket is full and empty the bucket. Repeat Step 1 and 2 as often as necessary to remove 25 percent of the water. Aquarium water is an excellent fertilizer and so can be used to water plants. Save some used aquarium water for cleaning the filter.
- 10
  Fill a bucket with fresh water. Add warm or cold water as necessary to match the temperature with the aquarium water. Dose with water conditioner according to the manufacturer's instructions.
- 11
  Use the jug to gently add the new water to the aquarium, taking care to avoid disturbing the fish, plants and substrate. It may take multiple bucketfuls to fill the aquarium.
- 12
  Turn the heater back on.
Cleaning the Filter
- 13
  If possible, remove the filter and place in the bucket of saved aquarium water. Some larger filters such as external filters should be left plugged into the tank while their media is removed and cleaned.
- 14
  Take the filter apart and remove the filter media. This includes sponges, ceramic rings and plastic balls.
- 15
  Gently squeeze soft media in the water to remove dirt and use your fingers to rinse any hard media. Do not allow the filter media to come into contact with untreated water as the chlorine and chloramine will kill the essential filter bacteria.
- 16
  Use the small brush to gently clean any debris from the impeller of the filter.
- 17
  Place the media back in the filter. Replace any chemical media (such as carbon and zeolite) according to the manufacturer's instructions. Put the filter back together and place the filter back into the tank.
- 18
  Ensure the filter is primed by adding some aquarium water into the filter. Turn the filter back on.