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API FRESHWATER MASTER TEST KIT 800-Test Freshwater Aquarium Water Master Test Kit, White, Single, Multi-colored

  • Based on 31,321 reviews
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Style: Freshwater


Features

  • Contains one (1) API FRESHWATER MASTER TEST KIT 800-Test Freshwater Aquarium Water Master Test Kit, including 7 bottles of testing solutions, 1 color card and 4 tubes with cap
  • Helps monitor water quality and prevent invisible water problems that can be harmful to fish and cause fish loss
  • Accurately monitors 5 most vital water parameters levels in freshwater aquariums: pH, high range pH, ammonia, nitrite, nitrate
  • Designed for use in freshwater aquariums only
  • Use for weekly monitoring and when water or fish problems appear

Description

Most water problems are invisible to the eye. Quickly measure and modify the six aquarium levels that are most important to the health of your freshwater fish with the API FRESHWATER MASTER TEST KIT. To stay healthy and thrive, fish need properly balanced levels of ammonia, pH, high range pH, nitrite and nitrate. These levels can change rapidly and create harmful conditions when fish waste, uneaten food or other organic matter accumulate, or when untreated water is added. If left uncorrected, all of these can be harmful or even fatal to fish, with consequences such as reduction of oxygen, increase in stress and higher risk of disease. The API FRESHWATER MASTER TEST KIT measures these six parameters with scientific accuracy and provides professional results. It comes with four test tubes, a holding tray and computer calibrated, laminated color card. Just fill the test tubes, add the test drops and compare results to the color card. Then follow the recommendations on the card if action is required. With API aquarium products, it’s easy to keep a beautiful saltwater, freshwater or reef aquarium. For almost 60 years API has developed premium solutions with proven and effective results for your family and ours. API offers a range of testing kits, water conditioners, and nutritionally superior food, because we’re dedicated to making a better underwater world. They work to provide a safe, hospitable environment for fish such as tropical community fish, cichlids, goldfish and more. At API, we understand the rewards and relaxation of fishkeeping because we have a passion for fish too.

Is Discontinued By Manufacturer ‏ : ‎ No


Product Dimensions ‏ : ‎ 9.13 x 3.5 x 4.65 inches; 1.15 Pounds


Item model number ‏ : ‎ 34


Department ‏ : ‎ Unisex-Adult


Date First Available ‏ : ‎ June 20, 2004


Manufacturer ‏ : ‎ Mars Fishcare


Best Sellers Rank: #1,341 in Pet Supplies (See Top 100 in Pet Supplies) #2 in Aquarium Test Kits


#2 in Aquarium Test Kits:


Customer Reviews: 4.8 4.8 out of 5 stars (31,321)


Item Weight: 1.15 pounds


Department: Unisex-Adult


Manufacturer: Mars Fishcare


Item model number: 34


Date First Available: June 20, 2004


Item Package Dimensions L x W x H: 6.69 x 5.12 x 4.33 inches


Item Dimensions LxWxH: 9.13 x 3.5 x 4.65 inches


Item Weight: 521.63 Grams


Brand Name: API


Target Audience Keyword: fish


Directions: Follow the instructional booklet directions for individual testing of each water parameter, and test weekly for best results.


Warranty Description: Warranty


Model Name: API FRESHWATER MASTER TEST KIT 800-Test Freshwater Aquarium Water Master Test Kit, White, Single, Multi-colored


Color: Multi-color


Size: Single


Material: Plastic


Number of Items: 1


Style: Freshwater


Included Components: API FRESHWATER MASTER TEST KIT 800-Test Freshwater Aquarium Water Master Test Kit, White, Single, Multi-colored


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Monday, Jul 27

This item is non-returnable:

Non-returnable. Transportation of this item is subject to hazardous materials regulation

View our full returns policy here.

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Similar Products

Top Amazon Reviews

    • Accurate Results, But the Process Is a Bit Much
Style: Freshwater
This test kit is definitely accurate — I’ve used it side-by-side with other tests and it consistently gives clear, reliable readings. It covers everything I need for my freshwater tanks (ammonia, nitrite, nitrate, pH), and it’s saved me from some serious water parameter issues more than once. That said, the process isn’t exactly quick or convenient. You’ve got to measure out water into test tubes, shake bottles, time everything exactly, and match colors that sometimes look way too similar. It works, but it’s not something I look forward to doing, especially if I’m testing multiple tanks or running through every parameter at once. What I liked: - Very accurate and consistent results - Covers all the main water parameters - Plenty of tests per bottle - More reliable than strips or cheap alternatives What I disliked: - Takes a while to run a full round of tests - Color matching can be hard under certain lighting - Lots of little pieces to keep track of It’s a solid kit and does the job well — just be ready for a bit of a routine every time you use it. I keep using it because I trust the results, but I wouldn’t mind if they made the process a little more user-friendly. ... show more
Reviewed in the United States on June 9, 2025 by Ray C.
    • Accurate, Reliable, and Way Better Than Test Strips
Style: Freshwater
I picked up the API Freshwater Master Test Kit when setting up my 6-gallon planted tank, and it’s been a huge upgrade over the test strips I started with. The strips were frustrating—hard to read, not very precise, and the gaps between values made it difficult to really understand what was going on in my tank. With this kit, the results feel much more accurate and consistent. I actually feel confident making adjustments based on the readings now. It’s also just a better overall experience. The process is straightforward, and there’s something oddly fun about it—it definitely gives off “mad chemist” vibes in the best way. ... show more
Reviewed in the United States on March 24, 2026 by Kaleigh
    • Great price kit that helps maintaining excellent water parameters
Style: Freshwater
Safe to use, good quality and has instructions. Size is great which means the kit lasts forever, it doesn’t smell. Easy to use with clear instructions. Brochure looks great and good material. Price beats all sellers.
Reviewed in the United States on March 2, 2026 by Saif
    • Good value for your money.
Style: Freshwater
Amazing kit! It helps continuously check the water parameters in my tanks to keep my fish, shrimps, and snails healthy. It's a great value for your money. It's safe to use; however, if you get the product on your hand, it will stain, lol.
Reviewed in the United States on March 24, 2026 by Mariah Nelson
    • Easier than high school chemistry, but similar lab rules apply
Style: Freshwater
Have you passed high school chemistry? (And by pass, I mean be able to follow the rules while in a lab?) Then great! You'll have no problem using this test kit! However, be aware the instructions are like stupid tiny. I'm only 20 and even with reading glasses on top of my regular glasses these instructions are tiny. API offers a .pdf version of the instructions on their website, so I recommend those more than the little booklet. I also recommend one of those little syringes for like pet medication or human medication. It makes getting the water in the tubes a lot easier and with good accuracy. A lot of reviews mention the test tube caps not being tight when capped. I haven't had this problem, but also when I invert the tubes, I hold my finger on the cap and at the bottom of the test tube. This was a habit I picked up in college chemistry because sometimes it better to be safe than sorry. Gloves aren't necessary, but if you feel safer (especially since some of the chemicals are corrosive) then ball out with gloves! A lot of reviews also mention the nitrate test. I'm not a biologist, so I can't say the accuracy, however, make sure you read the instructions REALLY good as it's completely different than the others. You add 10 drops of solution bottle 1, shake the tube, shake solution bottle 2 for 30 seconds, add 10 drops, shake the tube for a minute, then wait the 5 minutes to develop. My few complaints is why I'm giving this a 4/5 stars because I feel like they really hinder the product. There's simply not an appropriate number of tubes. There's 5 tests, but only 4 tubes. Beyond that, they should really have 6 tubes since accidents are super prone to happen with tiny test tubes like this. Even beyond this, I feel a silicone or even plastic caps that screw with a rubber seal would be icing on the cake to eliminate the leaking and hardening issue. I'm also not buying API's 24 kit of tubes for a few extra tubes, that's just ridiculous. My next complaint is I believe they should add the GH and KH test in with this kit. pH, GH, and KH are usually all related to each other, so having that in the kit rather than paying $10 separately for it. I'd rather get it with the kit and pay 5-7 dollars more for the kit. To feed off some other reviews, adding the syringe like I mentioned would be better too since a lot of people probably won't think about it. Finally, I think a chlorine test would be great since it's toxic to most fish. However, I do believe in giving credit where credit is due and this kit is affordable which is great for those just starting to get into the hobby! I think the hobby is gate-kept by super expensive products, so having something like this that isn't $50+ is really helpful for those just starting out! I also love the size of this kit, it's easy to store. No test kit will probably ever be 100% accurate nor will they probably ever match up, but I feel this is good for America's market. I say that because I've used Sera, which is imported from Germany, and it's super nice with detailed and intense instructions which makes the tests feel a bit more accurate than this high school chemistry project. (Sorry API). However, the $80 keeps me from repurchasing and instead, buy this one. So, I guess that's the magic of capitalism and having other bills to pay rather than spending $80+ on a water testing kit. Even after being in the hobby since I was in middle school, I feel a lot of the prices in this hobby prevent people from advancing further and wanting to get into saltwater, reefs, or ponds. I stick with freshwater simply because it's the cheapest and easiest. Overall, recommend. 7/10, just be aware and take some of the recommendations some reviewers have already said and it should be smooth sailing. ... show more
Reviewed in the United States on August 22, 2021 by Hayley
    • Great product 👌 👏
Style: Freshwater
Highly recommended.
Reviewed in the United States on July 17, 2026 by Mike Nieves
    • I will buy it again
Style: Freshwater
Review Image by Jesse Garcia
Review Image by Jesse Garcia
Review Image by Jesse Garcia
Review Image by Jesse Garcia
Review Image by Jesse Garcia
Review Image by Jesse Garcia
Easy to understand the instructions. Comes in a portable case which is a perfect caddy to go from one aquarium to the next. No scent that I detected. The case is durable and has an easy storage system that holds each vile. The colors are easy to get a reading to match against and each bottle has a different color for color coded instructions. The helped me adjust my water parameters to better suit my tropical fish. Very effective. ... show more
Reviewed in the United States on July 4, 2026 by Jesse Garcia
    • Must have kit for monitoring fish tank
Style: Freshwater
Got this kit for monitoring my goldfish tank. Very easy to use with clear instructions. Overall very satisfied and think this is a very suitable test kit to start with. This kit tests for 2 things. (1) PH levels and (2) Ammonia, Nitrite, and Nitrate levels (i.e. the Nitrogen Cycle). The Nitrogen cycle as related to a fish tank is as follows... Your fish gives off waste products, which Ammonia is a major component. When Ammonia levels in the tank go to high the fish can get burns, sick and can die. At some point your tank should develop bacteria that convert the Ammonia to Nitrite (this bacteria can live in the gravel and the filter. Also this bacteria is killed by tap water that has chlorine present so this is why you don't wash gravel with tap water. Also this is why you should not change all filter elements at once as you may be eliminating too much of your bacteria colonies). Once the bacteria that do this develop a large enough colony your ammonia levels should go to zero. Before the colony of bacteria is developed your tests for Ammonia should show some level present. You want to make sure that the level does not go to high. To reduce Ammonia levels you can either do water changes, use a filter that removes Ammonia or there are additives that can be added to reduce the levels as well. The next step is the bacteria converts the Ammonia to Nitrite. Nitrite levels if they go too high are bad for fish. Initially Nitrite levels will tend high (similar solution for excessive Ammonia levels will work for Nitrite as well). Eventually a colony of bacteria will develop that convert Nitrite to Nitrate. Once the colony reaches maturity your Nitrite levels should come up as zero on your tests. The final step (well not final if you use plants, which is more complicated) is as mentioned above the Nitrite being converted to Nitrate. When the bacteria colonies are fully removing all the Ammonia and Nitrite the tank is called cycled. At this point the major concern is that Nitrate levels should not go too high. The fortunate thing is that fish can tolerate relatively high levels of Nitrate as compared to Ammonia or Nitrite. I would think most cases where fish are not faring well, probably the Ammonia or Nitrite levels are high and the Nitrate is fine. In any case you will need to test for Nitrate probably no more frequently than every few weeks to few months (depends on your tanks size and number of fish) to make sure the levels are not getting to high. The solution for high levels is the same as for Ammonia or Nitrite, namely water changes, filtering, and additives (I have stayed away from additives but they are an option). This kit gives you everything you need to test for this critical cycle and is probably all you need for most fish tanks to help you keep your fish healthy for a long time. ... show more
Reviewed in the United States on September 1, 2013 by matt1234

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