Is 70 humidity too high for incubator?

fertilized egg

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Humidity plays the lead role in the delicate dance of hatching eggs, setting the stage for a thriving embryo or a hatching mishap. The art of incubation requires warmth and the embrace of the right humid environment, without which the precious cargo might either patch from dryness or suffocate in excess moisture. The stakes are high: stray too far on this hygrometric scale, and the life within risks premature end, plagued by developmental woes or microbial foes. Within this fragile equilibrium context, we pose a question fraught with implications for hatchlings’ fate: Is 70% humidity too high for an incubator?

70 humidity

70 Humidity Too High for Incubator?

General Guidelines for Incubation Humidity Levels

Optimal humidity levels during incubation typically range between 40-60% relative humidity (RH) for most species. When humidity falls too low, below 25% RH, the risk is dehydration of the embryo, leading to stunted growth or complete developmental failure. 

Conversely, if humidity soars above 60% RH, the chance of oversaturation arises. This excess can hinder air exchange and even drown the embryo. Both extremes can thwart the hatching process, hinting at the precision required in incubation practices.

Understanding Relative Humidity (RH) in Egg Incubation

Relative humidity measures water vapor concentration in the air, gauged against its capacity at a given temperature. With a temperature rise, the air’s potential to retain moisture escalates, making RH dependent on the amount of moisture present and the ambient warmth.

RH Calculations

To calculate RH, one must consider the current vapor pressure against the saturation vapor pressure at the same temperature. This can be handled by hygrometers or psychrometers, which provide readings by comparing wet-bulb and dry-bulb temperatures.

Ideal Range for Egg Development

During the initial stages of incubation, an RH of 40-50% is generally recommended, promoting proper moisture reduction within the egg. In the final days, often termed ‘lockdown’, the humidity should be increased to 65-75% RH to minimize the risk of the chick sticking to the shell and to assist in the hatching process.

humidity chart

Monitoring and Controlling Humidity Levels

Hygrometers and digital humidity controllers are often employed to monitor and adjust incubator humidity. These devices can provide ongoing readings and sometimes automate humidity adjustments with built-in humidifiers or dehumidifiers.

Best Practices for Maintaining Optimal Humidity

  • Consistent Monitoring: Regularly check humidity levels with reliable tools and adjust as needed.
  • Ventilation Management: Proper ventilation is critical as it regulates air exchange and moisture levels. Adjust ventilation settings according to the incubator’s instructions and outside humidity conditions.
  • Water Tray Regulation: Adding or removing water from the incubator’s tray can increase or decrease humidity respectively. Follow the incubator’s guidelines for managing water levels.
  • Environmental Considerations: The external environment plays a role; a humid climate may require less added water, while dry climates might need frequent adjustments.
  • Egg Turning: Ensure eggs are turned correctly and frequently to promote even moisture loss and facilitate healthy development.
  • Calibration: Calibrate humidity devices occasionally to ensure accuracy.

Understanding Humidity in Incubation

Let me take you through a topic close to my heart: the importance of moisture in the air, or ‘humidity’, when we’re trying to hatch eggs. You see, getting the humidity right is super important for the little life that’s growing inside each egg.

The Science of Humidity and Egg Development

Water in the air can affect how an embryo develops inside an egg. Please think of the eggshell as it has tiny holes that let air and water pass through. A lack of adequate humidity can lead to an egg dehydrating beyond necessary, which may negatively affect the chick’s development. When the moisture is overly high, it prevents the proper amount of water from evaporating from the egg, creating issues for the chick as it strives to hatch.

Importance of Monitoring and Adjusting Humidity

I use some neat tools to ensure the eggs have just the right amount of moisture around them. There are gadgets called hygrometers that tell me exactly how much water is in the air inside my incubator. And trust me, keeping a regular eye on this is critical. Things can go south quickly if I need to remember about it or don’t check more often. The wrong humidity can mean no chicks hatching, and I don’t want that!

Ideal Humidity Range for the First 18 Days of Incubation

For successful incubation, maintaining an optimal humidity level is crucial. The recommended humidity range for the first 18 days typically falls between 45-55% for chickens, with other bird species, such as ducks and turkeys, requiring slightly higher levels, around 50-60%.

Reasons Behind Ideal Humidity Range:

  • Water Loss Regulation: Eggs lose water through their porous shells; proper humidity levels ensure the loss occurs steadily and is controlled.
  • Embryo Health: Adequate humidity is vital for the embryo’s health, as too little moisture can cause dehydration, while too much can drown the embryo.
  • Shell Condition: Proper humidity optimizes the eggshell condition for the eventual hatching process; it should not be too brittle or soft.

Ramifications of Deviation:

  • Low Humidity: This may lead to excessive water loss from the egg, resulting in a smaller air cell and a dehydrated, underdeveloped chick.
  • High Humidity: Inhibits the necessary evaporation of water, potentially leading to an oversized air cell and difficulties for the chick during hatching (e.g., “sticky chicks” syndrome).

Consequences of Excessive Humidity during Incubation

  • Egg Impact: Can retard the loss of egg moisture, impacting the size of the air cell and interfering with the chick’s development.
  • Embryo Development: Excess humidity can cause embryos to develop abnormally or even drown within the shell if the air cell becomes too small.
  • Hatchling Quality: Chicks might emerge weak or with health issues, and the hatch rate could also be significantly lower.
humidity effect on eggs

Environmental Factors Affecting Humidity Settings

  • Altitude: Higher altitudes have thinner air, which can hold less moisture. Incubators may require adjustments in humidity settings to compensate for this difference.
  • Atmospheric Pressure: Changes in atmospheric pressure can affect how moisture evaporates from the egg. Low pressure could mean higher humidity levels in the incubator.
  • Temperature: Temperature fluctuations can impact the relative humidity within the incubator. Moisture is more readily absorbed by warm air; adjusting humidity settings is necessary as temperature varies.

Monitoring Importance

  • Hygrometer Use: A hygrometer is essential for measuring the actual humidity levels within the incubator.
  • Regular Adjustments: Incubator settings may need to be adjusted frequently based on the readings from your monitoring devices.
  • Ventilation: Keeping the humidity and temperature in balance requires proper ventilation.

Managing Humidity Levels and Incubator Setting Adjustments

  • Start with Manufacturer’s Guidelines: Begin with the recommendations provided by the incubator’s manufacturer and adjust based on the specific needs of the bird species being incubated.
  • Daily Checks: Perform daily checks of both temperature and humidity levels.
  • Record Keeping: Keep accurate records of all measurements and adjustments for reference and improvements.
  • Adjust Water Levels: Add or remove water from the incubator’s pan to increase or decrease humidity.
  • Calibrate Equipment: Regularly calibrate your hygrometer and thermostat to ensure accurate readings.

The Lockdown Period and Humidity Adjustment

Define the “lockdown” period in incubation:

The “lockdown” period refers to the final stage of egg incubation, typically commencing three days before the expected hatch date. For chicken eggs, this is generally day 18 of incubation. During lockdown, the eggs are no longer turned, and the incubator is kept closed to maintain stable conditions, mirroring the natural process where a hen would settle in to hatch her eggs without leaving the nest.

Necessary Changes in Humidity During This Phase

  • Increased Humidity: Increasing the humidity to 65-75% during the lockdown phase for chicken eggs is standard practice.
  • Purpose: The heightened humidity helps soften the eggshell, making it easier for the chick to pip and hatch.

The Risks of High Humidity in the Lockdown Phase

List of Potential Adverse Outcomes when Humidity is Maintained at 70% or Higher:

  • Drowning Hazard: Chicks can drown if excessive moisture is inside the egg.
  • Mold Growth: High humidity levels can encourage mold growth within the incubator, which poses health risks to the embryos.
  • Hatching Difficulty: Oversaturation can lead to a “gooey” environment within the egg, making it difficult for chicks to fluff up and hatch effectively.

Discussing the Balance Between Necessary Moisture and Over-Saturation:

  • Monitoring: Careful monitoring of humidity levels with a reliable hygrometer is essential during lockdown.
  • Ventilation: Proper ventilation should be adjusted to ensure enough air exchange to prevent over-saturation.
  • Calibration: Ensure the hygrometer and other instruments are calibrated correctly for accurate readings.
  • Observation: Keep an eye on the eggs; condensation within the incubator or on the viewing windows could indicate that humidity is too high, and adjustments may be needed.

Tools and Accessories for Maintaining Proper Humidity


  • Mechanical Hygrometers: Employ materials such as strands of human hair that lengthen and shrink in response to alterations in atmospheric moisture.
  • Electronic Hygrometers: Utilize sensors, which are more common due to their digital interfaces and accuracy.
  • Psychrometers: The difference between the temperature of two thermometers is used to calculate humidity using the dry and wet bulb thermometers.
  • Dew Point Hygrometers: Measure the temperature at which dew forms, indicating the moisture level in the air.
humidity meter on incubator

Calibration and Accuracy

Proper calibration is critical for ensuring the accuracy of hygrometers. Over time, sensors can drift, leading to incorrect readings that could compromise humidity control. Following the manufacturer’s guidelines for calibration, using known humidity standards, such as saturated salt solutions, ensures reliability.

Advanced Humidity Control

  • These devices actively add or remove moisture from the air:
  • Portable units are suitable for homes or offices.
  • Industrial-grade systems manage large-scale environments, maintaining specific conditions for manufacturing or storage.

HVAC Systems with Integrated Humidity Control: Modern HVAC systems may include humidity control functions, offering centralized management of temperature and moisture levels.

Smart Controls: Sophisticated sensors connected to intelligent systems enable real-time adjustments based on fluctuating environmental conditions. This can be programmed to react to changes in occupancy, weather, and other factors.

Homemade Humidifiers: One can create a primary humidification effect by placing water containers near heat sources or using fans to blow air over damp cloths.

DIY Dehumidifiers: Substances like silica gel, calcium chloride, or rice can absorb moisture in small areas, acting as simple dehumidifiers.

Pros and Cons

  • Pros: Cost-effective and easily implemented.
  • Cons: Limited efficiency, unsuitable for precise control, and require regular maintenance.

Expertise Required

Implementing DIY solutions often requires little expertise, but ensuring that these methods don’t introduce other issues (like mold growth) does necessitate some understanding of air quality and moisture dynamics.

big incubator

Last words

Managing humidity levels is crucial for successful egg incubation. Proper humidity ensures healthy embryo development and prevents the egg’s contents from drying or becoming too saturated. 

Key points include maintaining specific humidity ranges tailored to the species being incubated and regular monitoring with reliable hygrometers. Answering the central question: precise humidity control optimizes hatch rates and chick health. 

To achieve incubation success, it’s vital to adhere to best practices, which involve diligently adjusting moisture content as needed and consistently engaging in education about the latest techniques and equipment for incubation. Remaining informed and vigilant in these practices is the cornerstone of practical egg incubation.

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