Search  for anything...
API

API PH TEST KIT 250-Test Freshwater Aquarium Water pH Test Kit, 4 Piece Set

  • Based on 3,224 reviews
Condition: New
Checking for the best price...
$6.98 Why this price?
Save $1.00 was $7.98

Buy Now, Pay Later


As low as $1 / mo
  • – 4-month term
  • – No impact on credit to apply
  • – Instant approval decision
  • – Secure and straightforward checkout

Ready to go? Add this product to your cart and select a plan during checkout.

Payment plans are offered through our trusted finance partners Klarna, Affirm, Afterpay, Apple Pay, and PayTomorrow. No-credit-needed leasing options through Acima may also be available at checkout.

Learn more about financing & leasing here.

Selected Option

Free shipping on this product

FREE 30-day refund/replacement

To qualify for a full refund, items must be returned in their original, unused condition. If an item is returned in a used, damaged, or materially different state, you may be granted a partial refund.

To initiate a return, please visit our Returns Center.

View our full returns policy here.


Availability: In Stock.
Fulfilled by Amazon

Arrives Sunday, Jun 14
Order within 4 hours and 48 minutes
Available payment plans shown during checkout

Protection Plan Protect Your Purchase
Checking for protection plans...

Size: Standard


Features

  • Contains one (1) API PH TEST KIT 250-Test Freshwater Aquarium Water pH Test Kit, including 1 bottle of testing solution, 1 color card and 1 test tube with cap
  • Helps monitor and adjust pH and prevent invisible water problems that can be harmful to fish
  • Accurately reads pH 6.0 - 7.6 and helps avoid fish loss
  • Because different geographies have different tap water conditions, and different fish need different pH levels to be healthy, API helps measure pH levels & detect pH fluctuation caused by fish waste, uneaten food and addition of tap water.
  • Use for weekly monitoring and when water or fish problems appear

Description

Keep your fish healthy and thriving by testing your aquarium water's pH regularly with easy-to-use API pH TEST KIT for freshwater aquariums. Testing water parameters weekly helps prevent invisible water problems that can be harmful to fish. pH is the measure of acidity of water, on a scale ranging from 0 to 14. A pH of 0 is the most acidic, while a pH of 14 is the most alkaline. Different geographies have different tap water conditions with different pH levels, while fish require a specific pH level to thrive. A pH of 7.0 is ideal when keeping a community aquarium containing a variety of tropical fish. Goldfish and livebearers prefer a pH of 7.5. Many Amazonian fish, like angelfish and neon tetras, prefer a pH of 6.5 to 6.8. Mollies and swordtails thrive at pH 7.2 to 7.5. API pH TEST KIT for freshwater aquariums test a wide range of pH levels from 6.0 to 9.0. Just dip a strip directly into your aquarium, and use the color-coded chart to determine if your water is safe or if adjustments are needed. Then follow the recommendations to treat the water – it's that simple! 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 ‏ : ‎ 1.5 x 2.38 x 5.13 inches; 2.4 ounces


Manufacturer recommended age ‏ : ‎ 1 month and up


Item model number ‏ : ‎ 28


Department ‏ : ‎ men, women


Date First Available ‏ : ‎ June 20, 2004


Manufacturer ‏ : ‎ Mars Fishcare


Best Sellers Rank: #22,459 in Pet Supplies (See Top 100 in Pet Supplies) #33 in Aquarium Test Kits


#33 in Aquarium Test Kits:


Item Weight: 2.4 ounces


Department: men, women


Manufacturer: Mars Fishcare


Item model number: 28


Date First Available: June 20, 2004


Item Package Dimensions L x W x H: 5.16 x 2.8 x 1.61 inches


Item Dimensions LxWxH: 1.5 x 2.38 x 5.13 inches


Item Weight: 68.04 Grams


Brand Name: API


Target Audience Keyword: Fish


Directions: pH should be tested weekly, since natural materials in the aquarium (such as fish waste and uneaten food) can cause pH changes. When keeping livebearers, goldfish, African Cichlids, marine fish, or invertebrates, use the API HIGH RANGE pH TEST KIT.


Model Name: FRESHWATER PH TEST KIT


Color: black


Size: Standard


Material: Plastic


Number of Items: 1


Style: pH


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Sunday, Jun 14

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

  • Klarna Financing
  • Affirm Pay in 4
  • Affirm Financing
  • Afterpay Financing
  • PayTomorrow Financing
  • Financing through Apple Pay
Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

Top Amazon Reviews


  • Works great
Size: Standard
Works great
Reviewed in the United States on December 18, 2025 by Trish

  • Simple yet Accurate
Size: Standard
Very accurate and simple pH test.
Reviewed in the United States on February 3, 2026 by Amazon Customer

  • Good Product--Poor Amazon Packaging
Size: Standard
The product is great. Unfortunately, Amazon's paper bag packaging is not. The product box inside the paper bag arrived smashed, so it's not going to be very useful for storing the PH test kit. Luckily, the glass vial inside was intact.
Reviewed in the United States on February 19, 2026 by MO

  • Quick and simple
Size: Standard
This is a very good PH test kit. It works and it's imple to use, so there's really not much more to say about it. I took off a star because I would have preferred the test tube to be larger. For anyone with spending a lot of time and effort keeping the PH of the water under control, I would recommend chosing fish that can tolerate a wide range of PH levels and preferrably those that prefer the natural PH of the water at your house. There are plenty to choose from. If the sales person at the petshop is not helpful, you can always look up the info online first. ... show more
Reviewed in the United States on December 26, 2013 by TH

  • Exactly as described
Size: Standard
Accurate, repeatable and consistent. Quick and easy
Reviewed in the United States on January 24, 2026 by Jeff from IL

  • Fairly accurate and easy to use. The testing liquid lasts for years and years
Size: Standard
Good value for money, easy to to use, fairly accurate and adequate for aquarium use. The testing solution will last for years and years if not used too frequently. I like this product.
Reviewed in the United States on April 22, 2024 by Neville R.

  • Used this trusted brand for many years
Size: Standard
I’ve used this product for many years to test my aquarium’s PH. Easy to use with accurate testing.
Reviewed in the United States on August 12, 2025 by Lois

  • Easy to use, basic pH test kit for your aquarium
Size: Standard
A perfect, easy to use pH testing kit. Comes with the tester tube and a plastic lid, a bottle of the solution and a results card. Fill the tube up to the line with aquarium water, drop 3 drops of the solution in, replace the lid, shake and hold up to the card to find out your results. Very basic, but a great price for a needed kit for any aquarium owner. Note: I did have to order this twice - the first kit was very poorly packaged. The box was crushed and the results card was missing entirely, which told me that it was already crushed when it had been packaged up to be sent to me. I submitted this info to Amazon and they sent me a free replacement. ... show more
Reviewed in the United States on May 11, 2017 by JayneDoah

Can't find a product?

Find it on Amazon first, then paste the link below.
Checking for best price...