Fritz Master Test Kit | All-in-One Liquid Test Kit for Freshwater & Saltwater Aquariums

The Fritz Master Test Kit packs every essential aquarium water test into one organized box — pH, Ammonia, Nitrite, Nitrate, KH (Alkalinity), GH, and Phosphate — with reagents and color cards for both freshwater and saltwater systems. With over 600 individual tests included, this is the all-in-one liquid kit that covers your daily, weekly, and disease-investigation testing without forcing you to buy seven different boxes.

Pair this kit with the rest of our water testing tools and water care supplies to keep your tank stable from setup through stocking.

Why choose the Fritz Master Test Kit

• 7 essential parameters in one box — pH, Ammonia, Nitrite, Nitrate, KH, GH, and Phosphate
• Freshwater AND Saltwater — one kit covers both system types, perfect for hobbyists running mixed setups
• 600+ tests total — months of testing for the average hobbyist, easily a year for a single tank
• Liquid reagent accuracy — significantly more reliable than dip strips, especially for low-range ammonia and nitrite readings
• Includes test tubes & color comparison cards — everything you need to start testing the moment you open the box
• Made by Fritz Aquatics — a US-based, hobbyist-trusted manufacturer of water conditioners, salts, and treatments

What's tested

How to use

• Rinse the included test tubes with aquarium water before each test to avoid cross-contamination from other reagents.
• Fill to the indicated line with tank water — accuracy depends on hitting the exact volume.
• Add the specified number of drops of each reagent, capping and inverting (do not shake) between additions when the instructions call for it.
• Wait the full reaction time before reading — most tests require 3–5 minutes of color development.
• Compare against the included color card in natural daylight or a neutral white light, viewing the tube against the white reference area.
• Record results in a tank log so trends become visible over time — a slow rise in nitrate or drop in KH is more informative than any single reading.

Specifications

Recommended Pairings

• Seachem Prime Water Conditioner — detoxifies ammonia, nitrite, and nitrate while you bring readings back into safe range
• Saltwater Refractometer with Hard Case — pair with the Master Kit for full reef monitoring (the Master Kit doesn't test salinity)
• Reef & Saltwater Salt Mixes — lock in your target salinity and alkalinity before you ever add water to the display
• Additives & Supplements — adjust KH, calcium, and trace elements based on your test results
• Shop all Fritz Aquatics products — water conditioners, salts, and treatments from the same trusted brand

FAQ

Can I really use this kit on both freshwater and saltwater tanks?
Yes — the reagents and reference cards in the Master Test Kit are formulated to read accurately in both freshwater and saltwater. It's a great fit for anyone running multiple system types, or hobbyists who don't want to commit to two separate kits.

How accurate is a liquid kit compared to dip strips?
Significantly more accurate, especially at low concentrations. Dip strips are useful for a quick screen, but liquid reagent tests are the standard for cycling new tanks, troubleshooting fish health issues, and dialing in reef parameters where 0.5 ppm matters.

Does the Master Test Kit include calcium and magnesium tests?
No. The Fritz Master Test Kit covers the seven core parameters (pH, Ammonia, Nitrite, Nitrate, KH, GH, Phosphate). For dedicated reef chemistry testing, pair it with a calcium and magnesium kit such as Salifert or Red Sea Reef Foundation Pro.

How long do the reagents last after opening?
Most aquarium reagents stay reliable for 2–3 years if stored cool and out of direct sunlight. Note the open date on each bottle and replace any reagent that has changed color or behavior.

Is local pickup available?
Yes — Squeaky's Aquatics is a local pickup store. Order online and pick up in-store, or come browse the test kit aisle in person.