Fritz Dark Water

Turn any aquarium into a natural blackwater retreat. Fritz Dark Water is a concentrated almond leaf extract that releases the tannins and humic acids found in Indian almond (Terminalia catappa) leaves, tinting the water a natural tea color, gently lowering pH, and creating the soft, comfortable conditions that bettas, shrimp, and soft-water fish love. It is an easy, mess-free way to add blackwater benefits without waiting for leaves to break down. Pair it with Fritz Catappa Leaves or Catappa Tea Bags, or browse all our water care.

Why You’ll Love It

• Instant blackwater, concentrated liquid tannins with no waiting for leaves to steep.
• Naturally lowers pH and gives the water a warm, natural tea-stained look.
• Releases humic acids and tannins with natural antibacterial properties that soothe fish.
• Precise control, dose to your target tannin level and top up easily during water changes.
• Safe for shrimp and soft-water species, and made in the USA by Fritz.

How to Use

• Shake well before use.
• Add 5 mL (1 tsp) per 1 US gallon (3.8 L), or 6 drops per cup (236 mL), to raise tannins by about 1 ppm.
• Dose during water changes and build up gradually to your desired tint.
• With livestock present, limit pH change to 0.2 units per day and add to a high-flow area of the tank.
• A 4 oz bottle treats up to 24 gallons.

Specifications

Ideal For

Bettas, shrimp (Neocaridina and Caridina), discus, tetras, angelfish, killifish, and other soft-water or blackwater species, plus planted and biotope aquariums.

Complete Your Setup

• Add botanicals with Fritz Catappa Leaves, Catappa Tea Bags, or the Fritz Nature Box.
• Care for bettas with Fritz Betta Guard.
• Shop all Maintenance & Water Care and Additives & Supplements.

FAQ

Will it stain my tank?
It tints the water a natural tea color that clears with water changes or activated carbon. Very porous decor may lightly tint over time.

Does it lower pH a lot?
It gently lowers pH through tannins and humic acids. Dose gradually and monitor pH, especially when livestock are present.

Is it safe for shrimp?
Yes. Shrimp especially benefit from the tannins. Add it gradually to let them adjust.

How is this different from catappa leaves?
Same botanical benefits in a concentrated liquid, so you control the tannin level precisely without waiting for leaves to break down.