What is the Hydra Catalyst System?

The Hydra Catalyst System is a two-part nutritional system developed to accelerate and control the biological cycling process in aquariums without fauna.
It provides the necessary substrates and nutrients to stimulate the rapid establishment of nitrifying bacteria responsible for the nitrogen cycle.

The system consists of:

• Catalyst ONE provides the key initial substrates and nutrients.
• Catalyst TWO provides nitrite and complementary chemical support for the second phase of nitrification.

The two parts must always be used together.

Why is it important to cycle without wildlife?

Cycling is the process by which the aquarium develops the biological capacity to convert:

• Ammonia → Nitrite → Nitrate

During this process, the presence of fish can result in:

• severe stress
• ammonia or nitrite poisoning
• higher mortality and disease

Cycling without fauna allows the biofilter to fully develop before the introduction of fish, ensuring a safe and biologically stable environment from day one.

How does Catalyst work?

Catalyst does not replace bacteria nor does it perform chemical conversion.
Its function is to nourish and stimulate the growth of bacterial colonies by providing:

• controlled sources of nitrogen compounds
• supporting minerals and nutrients
• chemical conditions favorable to nitrification

In this way, the bacteria responsible for the nitrogen cycle establish themselves more quickly and in greater density, allowing the system to reach functional biological capacity in less time.

How to use — step by step

Preparation

1. Fill the aquarium with treated water (without chlorine/chloramines).
2. Turn on the filter and oxygenation.
3. Adjust pH and KH if necessary.
4. Reduce or turn off the lighting.

Day 1 - Aquarium set up — Daily dosage

Add this every day:

• 5 ml of Catalyst ONE per 100 L
• 5 ml of Catalyst TWO per 100 L

Always apply both parts, preferably at the same time of day.

Do not change the water during this phase.

When to test and how to interpret

First assessment: Day 8

Test 24 hours after the last dose :

• Ammonia (NH₃/NH₄⁺)
• Nitrite (NO₂⁻)

Interpretation:

✅ Functional cycle

• Ammonia ≈ 0 ppm
• Nitrite ≈ 0 ppm
• Nitrates present

The biofilter can process the load in 24 hours.

⏳ Cycle still under development

• Ammonia and/or nitrite still detectable.

→ Continue daily dosing and repeat tests after 3 more days, until the cycle is complete.

The cycle is complete when the system completely eliminates ammonia and nitrite within 24 hours after the last dose. This elimination may take longer if nitrates are already present in measurable quantities (5-10 ppm). Perform a new test 12-24 hours later, without dosing CATALYST, and confirm by testing if ammonia and nitrites have decreased and nitrates have increased compared to the previous test. Your cycle is functional and the aquarium is ready to receive fish when ammonia and nitrites = 0.

Warning: In cases of insufficient/weak biological filtration (too little biological media, low flow rate, low filter volume) for the liters of your aquarium, even with a complete cycle it may take more than 24 hours for all the ammonia and nitrites to be processed by the bacteria and for the values ​​to reach 0.
In this case, perform another test after another 12-24 hours without measuring CATALYST.
Update the filter as soon as possible.

Important recommendations

• Maintain high oxygenation throughout the process.
• Avoid bright lighting in the early stages.
• Monitor pH and KH if possible.
• Do not introduce fauna before complete confirmation of the life cycle.
• Avoid extensive filter cleaning during cycling.

What to do after cycling

Once the cycle is confirmed:

1. Perform a partial water change if necessary to reduce nitrates.
2. Adjust the lighting to the aquarium's normal settings.
3. Introduce plants (if they are not already present)
4. Introduce wildlife gradually.

For additional biological reinforcement and maintenance of stability, Hydra BioCore can be used as a supplement after cycling.