Aquarium Test Kits: What to Test and Which Kit
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You can't see ammonia or nitrite, and both can kill fish at low levels. Testing is how you know what's going on. Science below is from University of Florida fact sheets and Aqueon; product details are from API and the listings. We haven't tested the kits.
Why test
UF: "Ammonia is colorless and, even at levels toxic to fish, odorless. Therefore, the only way ... to know if ammonia is present is to test the water." UF adds that "in healthy ponds and tanks, ammonia levels should always be zero" and that nitrite "is toxic to fish at levels as low as 0.10 mg/L."
What to test and what you want to see
| Test | Target | Source |
|---|---|---|
| Ammonia | Zero | UF; Aqueon: "The only safe ammonia level is zero." |
| Nitrite | Zero | Aqueon: "The only safe nitrite level is zero." |
| Nitrate | Under 50 ppm | Aqueon: above 50 ppm is "undesirable" |
| pH | 6.8 to 7.8 for most tropicals | Aqueon |
More detail in aquarium water parameters.
Liquid kits
API's Master Test Kit "measures pH, high range pH, ammonia, nitrite, and nitrate," with seven solutions, four tubes and a color card. API says one kit allows "over 800 tests." For ammonia alone, API's ammonia kit reads 0 to 8 ppm, per the listing.
API Freshwater Master Test Kit
- Tests pH, high-range pH, ammonia, nitrite and nitrate, per the listing
- 7 test solutions, color card and 4 tubes
- Listed as 800 tests; freshwater only
API Ammonia Test Kit (130 tests)
- Reads ammonia 0-8 ppm (mg/L), per the listing
- Fresh or saltwater
- Listing suggests several tests a week when starting a new tank
Test strips
API's 5-in-1 strips test pH, nitrite, nitrate, KH and GH; Tetra's 6-in-1 also tests hardness, alkalinity and chlorine. Neither lists ammonia, per the listings. They're handy for quick checks and hardness, which the Master Test Kit doesn't measure.
API 5-in-1 Test Strips (100 count)
- pH, nitrite, nitrate, carbonate (KH) and general hardness (GH), per the listing
- Dip and compare colors
- Fresh or saltwater; no ammonia pad
Tetra EasyStrips 6-in-1 (100 count)
- Nitrate, nitrite, hardness, chlorine, alkalinity and pH, per the listing
- Dip, wait 60 seconds, read
- No ammonia pad
Comparing them head to head: API Master Test Kit vs test strips.
A testing gotcha
UF says many "water conditioners" and ammonia binders cause false-high ammonia readings with Nessler-type kits; salicylate kits aren't affected. Seachem gives the same caution about its Prime conditioner. If you use a binding conditioner and your ammonia reading looks off, that may be why.
FAQ
Why test?
Ammonia is invisible and odorless.
How often?
Weekly, more during cycling.
Strips and ammonia?
The API 5-in-1 and Tetra 6-in-1 strips don't.