Shortlist · Water changes and testing
Water-change tools and test kits
Two faucet water changers, a mini siphon vacuum, a liquid master test kit and a continuous ammonia monitor, with what each maker documents and leaves out.
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The short version
A water-change routine needs a way to move water and a way to know when the water needs attention. Merck lists both, monitoring water quality and a regular schedule of water changes, as part of preventive fish care.[1] These five tools cover the two jobs. Each is listed with what its maker documents and what it leaves out.
Faucet water changer (threaded faucets)
Python No Spill Clean and Fill, 25 ft
Pick it if: Tanks within 25 ft of a threaded faucet
- Why it's here
- Drains and refills from the sink without buckets, and Python documents its faucet fit: a 69HD brass adapter for threaded faucets, with MABA or FEBA adapters for some.
- Watch out
- Not every faucet fits; no flow rate is published. On Amazon, check that 'Ships from / Sold by' shows Amazon.com or Python.
- Feeder capacity
- Not stated
- Power source
- Not stated
- Noise (published measurement)
- Not stated
- Air flow (published measurement)
- Not stated
Faucet water changer (check Aqueon's faucet diagram)
Aqueon aquarium water changer, 25 ft
Pick it if: Tanks within 25 ft of a faucet on Aqueon's diagram
- Why it's here
- Drains and refills from the sink with an included multi-connection faucet adapter; Aqueon publishes a diagram of compatible faucet types.
- Watch out
- No flow rate is published, and Aqueon's where-to-buy page does not link Amazon. On Amazon, check that 'Ships from / Sold by' shows Amazon.com or Aqueon.
- Feeder capacity
- Not stated
- Power source
- Not stated
- Noise (published measurement)
- Not stated
- Air flow (published measurement)
- Not stated
Siphon gravel vacuum for small tanks
Aqueon siphon vacuum gravel cleaner, mini (5 in)
Pick it if: Nano and betta tanks up to 5 gallons
- Why it's here
- Aqueon lists the mini, with a 5 in tube and 6 ft hose, for 1-5 gallon aquariums, primed by moving the intake tube up and down.
- Watch out
- Sized for 1-5 gallon tanks only; larger tanks need a larger Aqueon size, which is not in our catalog. On Amazon, check that 'Ships from / Sold by' shows Amazon.com or Aqueon.
- Feeder capacity
- Not stated
- Power source
- Not stated
- Noise (published measurement)
- Not stated
- Air flow (published measurement)
- Not stated
Liquid test kit for routine checks
API Freshwater Master Test Kit
Pick it if: Any freshwater tank on a regular testing routine
- Why it's here
- API's kit measures pH, high-range pH, ammonia, nitrite and nitrate with seven test solutions, the core readings for routine water checks.
- Watch out
- Its ammonia reading should not be expected to match a free-ammonia monitor such as Seachem's. On Amazon, check that 'Ships from / Sold by' shows Amazon.com or API.
- Feeder capacity
- Not stated
- Power source
- Not stated
- Noise (published measurement)
- Not stated
- Air flow (published measurement)
- Not stated
Continuous free-ammonia monitor
Seachem Ammonia Alert, 2-pack
Pick it if: A between-tests warning in tanks that are not acidic
- Why it's here
- Stays in the tank and shows free ammonia continuously; Seachem says it responds in about 15 minutes to rising levels.
- Watch out
- Seachem says it is not recommended at acid pH, and its dealer list does not name Amazon. Sold as a 2-pack. On Amazon, check that 'Ships from / Sold by' shows Amazon.com or Seachem.
- Feeder capacity
- Not stated
- Power source
- Not stated
- Noise (published measurement)
- Not stated
- Air flow (published measurement)
- Not stated
How to choose
Moving water: faucet changer or siphon? A faucet water changer drains to the sink and refills from the tap, so it suits larger tanks within hose reach of a compatible faucet. Python and Aqueon both sell systems that do this; the deciding question is which one fits your faucet.[2][3] The Python vs Aqueon comparison covers the difference. For a small tank, a siphon gravel vacuum and a bucket is simpler: Aqueon lists its mini siphon, with a 5 in tube and 6 ft hose, for 1-5 gallon aquariums, and makes sizes up to a 16 in tube for bigger tanks.[4]
Testing: a kit, a monitor, or both? API's Freshwater Master Test Kit measures pH, high-range pH, ammonia, nitrite and nitrate, with seven test solutions.[5] It gives you a reading when you test. Seachem's Ammonia Alert stays in the tank and continuously detects free ammonia, responding in about 15 minutes to rising levels and about 4 hours to falling ones.[6] It is a between-tests warning, not a replacement for the kit.
Don't compare the two ammonia readings. Seachem's color thresholds are about 0.05 mg/L (ALERT), 0.2 mg/L (ALARM) and 0.5 mg/L (TOXIC) free ammonia, and it notes that 0.02 mg/L free ammonia equals 3.6 mg/L total ammonia in freshwater at pH 7.0.[6] The free vs total ammonia guide explains why. Seachem also says Ammonia Alert is not recommended at acid pH.[6]
How often
Merck's general maintenance schedule includes a water change every two weeks, with the amount depending on stocking level.[7] Python recommends a 5 to 10% change every other week for its users.[2] Neither is a rule for every tank; your test results tell you whether your routine is keeping up. Always dechlorinate new water: Merck says it should be dechlorinated, and Python recommends adding a water conditioner during refill.[1][8]
Buying notes
All five picks are Amazon listings. Aqueon's where-to-buy page offers only a store locator and does not link Amazon,[9] and Seachem's online-dealer list names specialist and pet retailers but not Amazon.[10] That does not make Amazon units fake, but it is why each pick asks you to check "Ships from / Sold by" before you buy.
Next
Questions
Do I need a test kit if I do regular water changes?
Merck lists monitoring water quality alongside regular water changes as part of preventive fish care, so the two work together.[1]
Why does my Ammonia Alert disagree with my test kit?
Ammonia Alert reads free (un-ionized) ammonia, which is only part of the total. Seachem notes that 0.02 mg/L free ammonia equals 3.6 mg/L total ammonia in freshwater at pH 7.0, so the two kinds of reading can't be compared directly.[6]
Which gravel vacuum size do I need?
Aqueon makes sizes from a mini 5-inch to a large 16-inch tube, and lists the mini for 1-5 gallon aquariums. Bigger tanks need a bigger size.[4]