Walmart US Ecommerce Website

GENERAL MERCHANDISE

PHARMACY

GROCERIES

VUDU

SPARK

PHOTO

ADVERTISING

SAVINGS CATCHER

GIFTCARDS

INHOME

AFFILIATE

ONEAPP

LOTUS

HELP

SMART_REORDER

GROCERY

CONV_COMMERCE

NEW AddonServicesRedesign Tue Jul 08 2025 9:54 PM PDT

NEW AddToCart Thu Jul 17 2025 11:47 PM PDT

NEW AddToCart Tue Jul 08 2025 9:53 PM PDT

NEW BrandLink Tue Jul 08 2025 10:10 PM PDT

NEW Breadcrumb Tue Jul 08 2025 9:36 PM PDT

NEW BuyBoxItemConditionsMultipleOffers Tue Jul 08 2025 10:49 PM PDT

NEW BuyBoxItemConditionsMultipleOffers Tue Jul 08 2025 9:52 PM PDT

NEW BuyBoxRatingsAndReviews Tue Jul 08 2025 10:12 PM PDT

NEW BuyBoxRefurbishedMessage Thu Jul 17 2025 11:54 PM PDT

NEW ConditionBadge Fri Jul 18 2025 12:00 AM PDT

NEW ConditionBadge Thu Jul 17 2025 11:53 PM PDT

NEW FreeShippingFreeReturns Tue Jul 08 2025 10:44 PM PDT

NEW FreeShippingFreeReturns Tue Jul 08 2025 9:48 PM PDT

I want shipping & delivery savings with

#0071dc

NEW Fulfillment Thu Jul 17 2025 11:48 PM PDT

#0053E2

NEW Fulfillment Tue Jul 08 2025 10:00 PM PDT

NEW GeneralWarningsPlaceholder Tue Jul 08 2025 10:34 PM PDT

Select the box to claim the offer. Get Walmart Cash when you receive your items.

NEW ItemDigitalRewards Tue Jul 08 2025 9:50 PM PDT

NEW ItemPageBadgeModule1 Tue Jul 08 2025 9:42 PM PDT

NEW ItemPageBadgeModule2 Tue Jul 08 2025 10:08 PM PDT

NEW ItemPageBadgeModule3 Tue Jul 08 2025 10:14 PM PDT

NEW ItemRelatedShelves Tue Apr 28 2026 7:13 PM PDT

Prices may vary online, in stores, and in-app.

Price Match Policy

Prices, terms, and availability may vary online, in stores, and in-app. Items ordered online may be available for pick up at store, shipping, or delivery. Some items may be available from Marketplace Sellers, who set their own prices, and are not eligible for price match. Items sold online by Walmart may be eligible for price match. See our

NEW LegalPriceDisclaimer Tue Jul 08 2025 10:43 PM PDT

Prices may vary online, in stores, and in-app. 

NEW LegalPriceDisclaimer Tue Jul 08 2025 9:44 PM PDT

NEW ListsAndRegistries Tue Jul 08 2025 10:07 PM PDT

NEW LowStockBadge Tue Apr 28 2026 11:36 PM PDT

NEW NutritionValuePlaceholder Tue Jul 08 2025 10:17 PM PDT

NEW OnlyAtWalmartInfo Tue Jul 08 2025 10:05 PM PDT

NEW OrganizationBadgesPlaceholder Tue Aug 19 2025 9:54 PM PDT

NEW PhysicalGiftCardOptions Wed Oct 15 2025 7:21 AM PDT

NEW PriceInformation Tue Jul 08 2025 10:41 PM PDT

NEW PriceInformation Tue Jul 08 2025 9:43 PM PDT

NEW ProductBasicInfo Tue Jul 08 2025 10:42 PM PDT

NEW ProductBasicInfo Tue Jul 08 2025 9:49 PM PDT

NEW ProductDescriptionPlaceholderATF Tue Jul 08 2025 10:14 PM PDT

NEW ProductDescriptionPlaceholder Tue Jul 08 2025 10:19 PM PDT

NEW ProductDirectionsPlaceholder Tue Jul 08 2025 10:28 PM PDT

NEW ProductFeedbackPlaceholder Tue Jul 08 2025 10:35 PM PDT

NEW ProductHighlightsPlaceholder Tue Jul 08 2025 10:15 PM PDT

NEW ProductImages Tue Jul 08 2025 9:40 PM PDT

NEW ProductIndicationsPlaceholder Tue Jul 08 2025 10:26 PM PDT

NEW ProductIngredientsPlaceholder Tue Jul 08 2025 10:32 PM PDT

NEW ProductMedicalGuidesPlaceholder Tue Jul 08 2025 10:25 PM PDT

NEW ProductName Tue Jul 08 2025 10:11 PM PDT

NEW ProductReturnPolicy Thu Jul 17 2025 11:51 PM PDT

NEW ProductReturnPolicy Tue Jul 08 2025 10:03 PM PDT

NEW ProductSpecificationsPlaceholder Tue Jul 08 2025 10:23 PM PDT

NEW ProductStickyBuyBox Tue Jul 08 2025 10:39 PM PDT

NEW ProductWarrantyPlaceholder Tue Jul 08 2025 10:30 PM PDT

NEW RefurbishedInfoPlaceholder Tue Jul 08 2025 10:21 PM PDT

NEW ReviewsPlaceholder Tue Jul 08 2025 10:37 PM PDT

NEW SellersSecondaryBuyBox Thu Jul 17 2025 10:13 PM PDT

NEW ServiceDisclosure Wed Oct 29 2025 7:27 PM PDT

NEW ServiceDisclosure Wed Oct 29 2025 7:30 PM PDT

NEW SoldAndShippedBy Thu Jul 17 2025 11:49 PM PDT

NEW SoldAndShippedBy Tue Jul 08 2025 10:02 PM PDT

B2B_subscription_illustration

New!

More savings, less stress.

Subscribe to get what you need, when you need it.  Cancel anytime.

NEW SubscriptionOptionsModule Tue Jul 08 2025 9:55 PM PDT

NEW Variants Thu Jul 17 2025 11:47 PM PDT

NEW Variants Tue Jul 08 2025 10:12 PM PDT

True

Compare with Similar Items

NEW ComparisonChart Updated

Sub Title 2

Title 2

NEW ItemCarousel Fri Feb 06 2026 8:32 AM PST

Bottom Sub Title 1

Bottom Title 1

NEW ItemCarousel Fri Feb 06 2026 8:59 AM PST

See Similar Items

NEW ItemCarousel Tue Feb 03 2026 7:21 PM PST

Frequently Bought Together

NEW SoftBundles Fri Feb 06 2026 8:24 AM PST

API Freshwater Master Test Kit, Aquarium Water 850 Test Kit

Instructions

Monitors and prevents invisible water problems leading to fish loss.

Fish Health Protection

Measures 5 vital freshwater parameters: pH, high pH, ammonia, nitrite, nitrate.

Essential Water Analysis

Provides 800 tests for freshwater aquariums.

Extensive Test Capacity

Features a simple 3-step process: fill, add, compare results.

Easy Water Testing

Provides recommendations for required corrective action.

Actionable Water Advice

Includes 1 laminated, computer calibrated color card.

Accurate Color Chart

Comprehensive Test Solutions

Durable Testing Vials

Supports weekly monitoring and rapid problem detection.

Proactive Problem Sensing

Freshwater Specific Use

<ul>  <li>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 plastic tubes with cap</li>  <li>Helps monitor water quality and prevent invisible water problems that can be harmful to fish and cause fish loss</li>  <li>Accurately monitors 5 most vital water parameters levels in freshwater aquariums: pH, high range pH, ammonia, nitrite, nitrate</li>  <li>Designed for use in freshwater aquariums only</li>  <li>Use for weekly monitoring and when water or fish problems appear</li> </ul>

Features

Count

Product line

Rec. use

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 glass test tubes, a holding tray, test tube rack 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 over 50 years, API has been creating innovative, research-driven solutions that make it easier to care for your fish and aquarium. API Aquarium Treatment Supplies are designed to work in conjunction with each other to provide best results to control algae, promote healthy bacterial growth and help control and mediate fish diseases and conditions such as ich and fin rot. They work to provide a safe, hospitable environment for fish such as tropical community fish, cichlids, goldfish and more. With API, you can spend more time admiring your fish, and less time scrubbing your tank. Make sure to use all products as directed in order to ensure the best results.

Brand

Manufacturer

Assembled Product Weight

Color

title_shipToHome_date_delivery

Ease Of Use

Clarity Of Instructions

For Aquariums

Ease Of Reading Results

Packaging

Storage Container

Test Coverage

Test Tubes

Value For Money

Color Chart

Accuracy

Water Conditions

Simple operation with minimal guidance required.

Size

I was using another brand dry strips (not impressed)  %26 read to try API Master Kit. A big difference.  Company does great job explaining why you do the specific tests %26 how to do each test.  I very much like on each solution it again lists how many drops you need. Very  nice case for test bottles %26 drops.  Will buy again.

API Testing is a great kit.

This kit is absolutely excellent. It's a bit pricier than buying water test strips, but more cost efficient in the long-run if you are getting into betta keeping and need a way to test your water regularly. It's also WAY more accurate than test strips and easy to use. Highly recommend for both veteran betta keepers and novices (like me) who realized they need to monitor their tank a little better to keep their betta friends happy and healthy. :-)

Must-have for any betta owner!

I read someone else say they regretted the kit did not come with a dropper, but I happened to have had one already.  IF you do not have a dropper, it would be very difficult to put the drops in the vials.

No problems

The best aquarium test kit. Just shop around for the best price .

The most recommended test kit

Works perfectly and the testing is spot on.

Great Test Kit

Easy to use and read test results. Would recommend this test kit.

API master test kit

I thought there was a tester for chlorine levels but there wasn’t.  All other test themes met my expectations

would be nice if delivery carriers would handle package with more caution...  Delivery person tossed the box on the ground like it was nothing cause for one of the bottles to leake out a lot... if you need this kit safe to your door i dont recommend delivery with Walmart.

It comes with a lot of hassle, and dipping, and DRIPPING, and measuring, and waiting.. 😞 
After finding the results I'm getting by using the test kit, I have decided that test strips are very dependable and really pretty much nail it for my needs.
I am actually beginning to believe that it's not necessary to get "overly, overly freaked out' about all your levels in your aquarium. First and most importantly, start out by using reverse osmosis water in your tank from a reputable source. Even the water coming out of those machines in front of the stores is much better than tap water. I checked that out with my test strips also... But try to get it from a water store. test it with your test strips before you put it in. It should be pretty pristine on all the levels presented on the stick.. It might be a little low on pH
R. O. water is a huge plus, right there. 
Secondly, you can look at the fish and see how they are functioning. You can read up on Google as to how your fish should be behaving or not behaving.. Are they clamping their fins.?? Yeah, you have a problem.. Are they staying away from the bottom, or always floating way near the top? Yeah, you may have a problem..  otherwise, if they seem to be happy and they seem to be healthy looking with no funky disease spots or anything like that, I would say your aquarium is a pretty happy place. Definitely do water changes.. Good ones.. Once a month. keep it scrubbed up inside. Make sure the temperature is good in your water for the type of fish you have. But don't get too overly concerned about it all. Constantly messing with it is not good, either. DEFINITELY have good frilltration. WAY over the top with the water cycling, as much as possible. Lastly, read up on how to take care of fish. Become knowledgeable and familiar with your hobby. Knowledge is power when it comes to taking care of fish. But don't get TOO  over- picky about it all, as I stated before. GOOD LUCK!

Just by test strips

I found this item cheaper. Of all places, it was on a very overpriced tropical fish website for less than it is here. There's 5 tests to be performed, but only 4 test tubes. Seems like they would've included 1 for each test, but that's just my opinion. Plus, the results can be tricky if you're not in totally bright lighting. Think medical lab - that's the kind of light you need to read this accurately. It's also easy to get the solutions mixed up due to the words "nitrite" and "nitrate" being do similar. I've done that more than once. Think I'll just go with test strips after this.

Overpriced, kinda confusing

Ease of use

Price

Ensure your aquarium's health with the API Freshwater Master Test Kit. Shop now!

API Freshwater Aquarium Master Test Kit - Accurate pH, Ammonia & Nitrite Levels for Safe, Fresh Fish Water

API Freshwater Master Test Kit, Aquarium Water 850 Test Kit

About this item

At a glance

How do you want your item?

More seller options (1)

How do you want your item?