Hydroponics offers a huge advantage: a controlled, soil-free environment without many of the contingencies typical of traditional farming. But "controlled" does not mean "immune."
Algae, molds and pathogens can still develop-and when they do, it is often because a seemingly trivial detail has been overlooked.

The good news? With a few targeted steps, it is possible to prevent them almost entirely.

Why algae, mold and disease find their way right into hydroponics

In hydroponics, the environment is rich in what life needs: water, nutrients, oxygen. If these elements are optimized, perfect plants grow.
If they get out of hand, unwanted organisms proliferate.

The three main reasons:

1. Light + water = algae

2. Stagnant moisture = mold

3. Insufficient hygiene = pathogens

Prevention starts here.

1. How to prevent algae

Algae develop whenever light and water come into direct contact.

What to do:

• Completely screen the tank.
  Opaque materials, closed lids, no light infiltration.

• Reduce exposure of roots to light.
  Any cracks should be closed.

• Avoid stagnation in irrigation lines.
  Moving water reduces algal growth.

• Keep nutrients and pH stable
  Algae prefer very unbalanced or old solutions.

Early signal to intercept

A slight green "film" on internal surfaces.
Taking action now prevents contamination that is more difficult to remove.

2. How to prevent mold and mildew

Molds do not live in water, but in excess moisture around plants.
They develop especially in the early stages of germination, when delicate parts are most vulnerable.

What to do:

• Ensure constant air exchange
  Where there is no ventilation, there is mold.

• Avoid condensation above plants.
  Too often results from unbalanced temperatures.

• Do not overwater
  Terrible, especially in the germination stage.

• Keep trays and surfaces clean.
  Even tiny residues can harbor mycelia.

Early signal to intercept

Whitish patina or fuzz on moist surfaces-a typical indicator of germination mold.

3. Diseases and pathogens: prevention at the "pro" level.

Pathogens in hydroponics (Pythium, Fusarium, etc.) strike especially when:

• the water is too warm,

• dissolved oxygen is low,

• hygiene is not strict.

What to do:

• Keep the water temperature between 18°C and 22°C.
  Above 24°C increases the risk of pathogens.

• Sanitize the system between cycles.
  No compromises.

• Use quality water
  Avoid chlorine, residues, external contamination.

• Oxygenate the solution properly
  Stagnant water is the ideal environment for pathogens.

Early signal to intercept

Roots starting to turn from white to beige/brown with abnormal odor.

4. The role of hygiene: the rule that eliminates 80% of problems

According to professional guidelines (and our field experience), hygiene determines most successes or failures.

Essential checklist:

• Wash tanks and trays every cycle

• Remove plant residues without exception

• Use dedicated, clean tools

• Avoid touching roots and seeds with unwashed hands

5. "Zero stress" prevention with automation and control

Most problems arise from parameters gradually deviating from optimal values.

In Tomato+ greenhouses (Horto2, Horto4, Horto Professional) these risks are drastically reduced by:

• Continuous water monitoring (EC and pH)

• Environmental sensors

• Intelligent automations

• AI-optimized growth plans

The entire ecosystem is designed to maintain stable conditions, minimizing the possibility of proliferation of external agents.

Conclusion

Preventing algae, mold and disease does not require chemicals or complex interventions:
it requires discipline, control and intelligent automation.

Following the basic rules allows you to:

• keep the nutrient solution clean,

• avoid plant stress,

• ensure consistent, high-quality production.

Thank you for reading this article. Keep following us to discover new content on hydroponics, vertical farming, and smart agriculture.
Tomato+ Team