Egg Incubator Humidity Start Ranges And Weight-Loss for Steady Hatching

You need to set the egg incubator humidity between 45% and 50% when you start incubation. This helps eggs lose moisture at a steady rate. Most eggs should lose about 11-13% of their original weight by day 18.

• Use a digital scale to track egg weight-loss.

• Check the air cell size to make sure eggs lose the right amount of moisture.

During incubation, keep the incubator closed as much as possible. You should only open the lid when you must check eggs or adjust humidity. Before hatching, increase humidity to 65-70% for a stable humidity level. This helps chicks break through the shell and keeps the membrane moist.

Key Takeaways

• Set the incubator humidity between 45% and 50% at first. This helps eggs lose moisture slowly and evenly.

• Use a digital scale to check egg weight-loss. Try to get 11-13% loss by day 18. Example: a 60 g egg should be about 52.8 g on day 18 (≈12% loss). This helps chicks stay healthy.

• Keep the incubator closed most of the time. This keeps humidity and temperature steady.

• Raise humidity to 65-70% for the last three days. This helps chicks hatch well.

• Candle eggs on days 7, 14, and 18. This lets you see air cell size and embryo growth.

• Change humidity slowly. Make small changes and watch what happens. This keeps embryos from getting stressed.

• Use checklists before incubation, every day, and during lockdown. This helps you remember each step for hatching.

• Clean the incubator well after each hatch. This stops germs and keeps eggs healthy next time.

Why Humidity Matters

Evaporation and Air Cell

You set humidity to control how much water eggs lose. Water leaves the egg through the shell. The air cell inside the egg gets bigger as water goes out. Chicks need this air cell to breathe before they hatch. If humidity is too low, eggs lose water too fast. The air cell gets too big. If humidity is too high, eggs keep too much water. The air cell stays small. The table below shows how humidity changes water loss and air cell size:

Try to keep humidity between 45% and 50% at the start. This helps eggs lose water slowly and lets the air cell grow well.

Risks of Low or High Humidity

Too little or too much humidity can hurt chicks. Low humidity can dry out eggs and slow chick growth. High humidity can also cause problems. Chicks may get too big and cannot move well inside the egg. Sometimes, extra fluid stays in the egg. This can make chicks drown when they try to hatch.

Tip: Both low and high humidity can cause problems—adjust based on weight loss and air cell. Watch humidity often to keep chicks safe.

Here is a table that shows how humidity affects chick health:

Membrane and Chick Health

Humidity changes the egg membrane and chick health. If humidity is wrong, eggs lose too much water. This can slow chick growth and weaken their immune system. The egg yolk and membrane feed and protect the chick. If eggs lose too much water, these parts do not work well. Chicks may be smaller and die more often, especially in layer breeds. The number of pores in the shell changes how much water leaves. This affects how chicks control water and hatch.

• Bad humidity can:

  • Cause water loss that slows chick growth and weakens immunity.

  • Make the egg membrane less able to protect the chick.

  • Lead to smaller chicks and more deaths.

  • Put stress on the chick’s immune system.

  • Change how chicks control water in their bodies.

Keep humidity steady and in the right range. This helps chicks grow strong and keeps their membranes healthy.

Egg Incubator Humidity Basics

Start Ranges

Set the right humidity when you start. Most experts say to keep humidity at 45–50% RH for the first 18 days (very dry rooms may need 50–55%—verify by weight loss and air cell size). This helps eggs lose water at a steady pace. If you use a forced-air incubator, set it to 99.5°F (37.5°C). For a still-air incubator, set it a little higher, about 101–102°F (38.3–38.9°C).

Here is a table that shows the usual humidity ranges:

Raise humidity to 65–70% RH for the last three days, called "lockdown." Higher humidity keeps the egg membrane wet and helps chicks hatch. Good airflow is important, too. As chicks grow, open vents more to let in fresh air. At lockdown, keep airflow strong but do not open the lid unless needed.

Tip: Always read your incubator’s manual for the best settings. Some models may need special steps.

Machine Differences

You should know how each incubator type works. Forced-air incubators have fans to move air around. These machines keep humidity and heat even everywhere inside. You can change humidity with built-in controls. Still-air incubators do not have fans. You must watch humidity and add water or sponges by hand. Humidity can be different in some spots because air moves slowly.

• Forced-air incubators:

  • Built-in humidity controls

  • Even humidity and temperature

  • Easy to change settings

• Still-air incubators:

  • You adjust humidity by hand

  • Humidity can be uneven

  • Use natural air movement

If you want less work, pick a forced-air incubator. If you like to do things yourself, a still-air incubator may be better.

Sensor Placement

You need good readings to control humidity. Put sensors away from sunlight, drafts, and heat. Place the sensor near the top of the eggs, but do not let it touch the shell. This spot gives the best reading for both humidity and heat. Use a digital thermometer, like the Govee H5074, for better results. Check your thermometer before each hatch to make sure it is right.

• Keep sensors away from light and moving air.

• Use digital thermometers for better readings.

• Check sensors before every hatch.

Note: Good sensor placement helps you avoid mistakes. This keeps humidity steady and gives chicks the best chance to hatch.

Humidity Control Methods

Adjust Humidity

You can change humidity in your incubator in different ways. The main goal is to keep humidity steady and in the right range. Here are some easy ways to do this:

• Use less water in the trays to lower humidity.

• Put wet sponges inside to make humidity go up.

• Add dry sponges or towels to soak up extra moisture.

• Advanced (optional): Use silica gel packs or desiccants like activated charcoal to take moisture out of the air—use with caution and monitor RH closely.

• Take out water trays for a short time if humidity gets too high, but watch the temperature.

Tip: Always check humidity after you make changes. Small changes work best to keep humidity steady.

Water Surface and Ventilation

The size of the water surface in your incubator changes humidity more than how deep the water is. You can control humidity by changing the water surface or using sponges. Here are some ways to do this:

• Use a shallow, wide dish of water to make humidity higher.

• Put a clean wet sponge inside if you do not have much space.

• Fill fewer water trays to stop too much moisture.

• If you only have one tray, make the water surface smaller.

• Open vents to let air move and help moisture leave.

• Use fans in forced-air incubators for better air flow, but do not point fans at eggs.

Note: Put sensors at the same height as the eggs and away from heaters for good readings. Keep the room steady to help control humidity.

Calibrating Instruments

Getting the right humidity reading is important for hatching eggs. You should check your hygrometer before every incubation. Here is an easy way to test your sensor:

1. Mix half a cup of salt with a little water in a small bowl to make a thick paste.

2. Put the hygrometer and the salt paste in a zip lock bag. Do not let them touch.

3. Leave the bag at room temperature for 12 to 24 hours.

4. Look at the hygrometer. It should say 75%. If it does not, fix the reading or get a new sensor.

• Use a hygrometer to check humidity.

• Set your digital incubator using a mercury thermometer.

• Test the hygrometer before you use it each time.

• Use two sensors if you can to double-check.

Emergency tip: If the power goes out, keep the incubator closed to hold humidity and heat. If you need to open the lid, do it fast and only when you must.

Weight-Loss and Air Cell Tracking

Calculate Weight-Loss

When you place your eggs in the incubator, you start a process where the eggs lose water through their shells. This water loss is important for the embryo inside each egg. You need to track this weight loss to make sure the chicks develop well. The best way to do this is by weighing the eggs at the start and then again at key points during incubation.

To get the best hatch rates, aim for each egg to lose about 11–13% of its starting weight by day 18. This range helps the embryo grow strong and healthy. You can use a digital scale for this job. Weigh each egg before you start incubating eggs. Write down the weight. Weigh the eggs again every few days, such as on days 7, 14, and 18. Enter the numbers into a notebook or a spreadsheet.

Here is a simple table to help you track weight-loss:

Tip: If the eggs lose weight too fast, raise the humidity in the incubator. If they lose weight too slowly, lower the humidity or increase ventilation.

You can use batch weighing if you have many eggs. Weigh a whole tray at once and divide by the number of eggs to get the average. This method saves time and still gives you good data for adjusting humidity.

Air Cell Monitoring

The air cell inside each egg grows as water leaves during incubation. The embryo needs this air cell to breathe before hatching. You can check the air cell size by candling. Candling means shining a bright light through the egg to see inside. You should candle on days 7, 14, and 18. This schedule lets you watch the air cell and the embryo’s growth.

When you candle, look for these signs:

• The air cell should get bigger as incubation goes on.

• The embryo should move and fill more of the egg.

• The air cell should match the size shown on air cell growth charts for each day.

You can use a simple list to remember what to check during candling:

• Day 7: Look for a small air cell and a moving embryo.

• Day 14: The air cell should be larger, and the embryo should be active.

• Day 18: The air cell should take up about one-third of the egg. The embryo should fill most of the space.

If the air cell is too small, the eggs are not losing enough water. Lower the humidity in the incubator. If the air cell is too large, the eggs are losing water too fast. Raise the humidity or close some vents.

Note: Candling helps you see both the air cell and the embryo. This makes it easier to spot problems early.

Fine-Tune Humidity

You can fine-tune the humidity in your incubator by using both weight-loss data and air cell size. Watch how much weight the eggs lose and how the air cell grows. Adjust the humidity if you see that the eggs are not on track.

• If the eggs lose less than 11% by day 18, lower the humidity to help them lose more water.

• If the eggs lose more than 13%, raise the humidity to slow down water loss.

• Always make one change at a time. Write down what you change and check the results at the next candling.

Here is a checklist to help you fine-tune humidity:

• Monitor egg weight-loss and air cell growth every week.

• Adjust humidity in small steps (about 5% at a time).

• Use candling to check the air cell and embryo activity.

• Keep records of all changes and results.

• Increase humidity to 65–70% during lockdown for safe hatching.

Remember: Good tracking and small adjustments help you get the best results when incubating eggs. The right humidity and air cell size give the embryo the best chance to hatch strong and healthy.

Hatching and Lockdown

Stop Turning

You reach the final stage of hatching chicks at home when you stop turning the eggs. On day 18, you need to remove the automatic egg turner from your incubator. Place the eggs on a non-slip surface, with the large end up or on their sides. Do not turn the eggs again. Chicks inside the eggs must settle into the right position for hatching. Stopping turning helps them line up to pip and hatch. If you keep turning the eggs, chicks may struggle to break through the shell. You want every chick to have the best chance to hatch strong and healthy.

Steps for stopping turning:

1. Stop turning eggs at day 18.

2. Remove the egg turner from the incubator.

3. Place eggs on a non-slip surface, large end up or sideways.

4. Leave the eggs undisturbed until hatching.

Raise Humidity

You need to raise humidity in your incubator during lockdown. The best range for hatching chicks at home is 65–70% relative humidity (RH). This level keeps the egg membrane moist and helps chicks pip and hatch. Add warm water to the incubator trays or use damp sponges to increase humidity. Use a hygrometer to check humidity often. If humidity drops, add more warm water. High humidity during lockdown prevents chicks from losing too much moisture. Chicks need a moist environment to break through the shell and avoid getting stuck.

• Increase humidity to 65–70% RH for the last three days.

• Add warm water to trays or use damp sponges.

• Monitor humidity with a hygrometer.

• Adjust humidity by 5–10% if needed.

The right humidity helps chicks pip, hatch, and fluff up after they leave the egg. If humidity is too low, chicks may dry out and stick to the shell. If humidity is too high, chicks may have trouble breathing. You want to keep humidity steady for the best hatch rates.

Minimize Lid Openings

During lockdown, you must keep the incubator closed as much as possible. Opening the lid can cause humidity and temperature to drop quickly. Chicks need stable humidity to hatch safely. Avoid opening the incubator during the last three days. Only open the lid if you see a chick in trouble or need to add water. Limit disturbances to keep humidity steady.

• Keep the incubator closed during lockdown.

• Only open the lid for emergencies or adding water.

• Stable humidity helps chicks pip and hatch.

Watch for pips on the eggs. Pips look like small cracks or holes where chicks start to break through. You may see internal pipping first, then external pipping. Most chicks hatch without help. If you see a chick struggling and the membrane looks dry and hard, you may need minimal intervention. Wait until most chicks are fluffed before moving them. Fluffed chicks look dry and soft, ready to leave the incubator.

If you wonder what to do on hatch day, keep the incubator closed, watch for pips, and let chicks fluff up before moving them. This helps every chick hatch strong and healthy.

Troubleshooting Humidity

Air Cell Too Large/Small

Sometimes, the air cell inside your eggs is not the right size. This means the humidity in your incubator is not set right. If the air cell is too small, eggs are not losing enough water. If the air cell is too big, eggs are losing water too fast. Both problems can make it harder for chicks to hatch and stay healthy.

Here is a table to help you see what causes these problems and how to fix them:

Keep humidity around 58–60% until three days before hatching. Then raise it to 65% or more for the last days. This helps the air cell get to the right size. If humidity is too high, eggs can take in too much water. This can make eggs swell, cause chicks to look strange, and lower hatch rates. A small air cell also means the chick does not get enough air.

Tip: Candle eggs on days 7, 14, and 18. Check the air cell size and change humidity a little if needed.

Sticky Chicks

Sticky chicks happen a lot when hatching eggs. You might see chicks stuck in the shell or covered in sticky stuff. This usually happens if humidity is too high during incubation. Other reasons are low temperature, not turning eggs enough, old eggs, or eggs that are too big.

• Main causes of sticky chicks:

  • High humidity during incubation

  • Low temperature in the incubator

  • Not turning eggs enough

  • Using eggs that are old or too big

Managing humidity helps keep the shell membranes soft. When humidity is right, the membranes stay wet and soft. This makes it easier for chicks to hatch. If humidity is too high, the membranes get sticky and trap the chick. If humidity is too low, the membranes dry out and get hard.

Note: Keep humidity steady and turn eggs often. This helps stop sticky chicks and lets them hatch strong.

Humidity Not Recovering

Sometimes, after you open the incubator, humidity does not go back to normal. This can hurt your hatch. You can try different ways to help humidity recover:

• Lower water by using fewer water trays.

• Put damp sponges inside to raise humidity without too much water.

• Open vents or use a small fan to let extra moisture out if humidity is too high.

• Add dry sponges or towels to soak up extra water.

• Use silica gel packs to take away moisture without changing the heat.

• Advanced (optional): Add desiccants like activated charcoal to lower humidity—use with caution and monitor RH closely.

• Take out extra water trays for a short time to drop humidity.

Check the humidity reading after you make changes. Make small changes for the best results. Keep the incubator closed as much as you can to help humidity recover fast.

Temperature Gradients

Temperature gradients inside your incubator can affect how well you control humidity. You might notice that some eggs hatch better than others. This often happens because the temperature is not the same everywhere inside the incubator. When you have hot and cold spots, humidity can change from one area to another. You need to understand how temperature and humidity work together to get steady hatching results.

If you use a still-air incubator, you may see bigger temperature gradients. The air does not move much, so the top of the incubator can be warmer than the bottom. Forced-air incubators use fans to mix the air. This helps keep the temperature and humidity more even. You should place your eggs in the middle of the incubator if you can. This spot usually has the most stable conditions.

Here are some signs that temperature gradients are causing problems:

• Eggs near the edges hatch later or earlier than those in the center.

• Chicks look weak or have trouble breaking out of the shell.

• The air cell size is different in eggs from different trays.

• Humidity readings change when you move the sensor to a new spot.

You can check for temperature gradients by using several thermometers. Place one at the top, one at the bottom, and one in the middle. Write down the readings every day. If you see a difference of more than 1°F (0.5°C), you need to make changes.

Tip: Use a small fan to help mix the air in a still-air incubator. Make sure the fan does not blow directly on the eggs.

You can fix temperature gradients and keep humidity steady by following these steps:

1. Place eggs in the center of the incubator.

2. Use a fan to mix the air if your incubator does not have one.

3. Check temperature and humidity at different spots.

4. Move the sensor to egg level for the best readings.

5. Avoid stacking trays too high, which can block airflow.

Here is a table to help you spot and fix temperature gradients:

You want to keep both temperature and humidity steady for all eggs. This helps every chick develop well and hatch strong. If you notice problems, make small changes and check your results. Good airflow and careful monitoring help you avoid trouble with temperature gradients.

Checklists and Cleaning

Pre-Incubation Checklist

Before you start incubating eggs, you need to prepare your incubator and supplies. A good setup helps you keep humidity and temperature steady. Follow this checklist to get ready:

1. Clean the incubator with warm water and mild detergent. Rinse and dry all surfaces.

2. Check that all parts work, including the fan, heater, and water trays.

3. Calibrate your digital hygrometer and thermometer. Place them at egg level inside the incubator.

4. Set the incubator to 99.5°F (37.5°C) for forced-air or 101–102°F (38.3–38.9°C) for still-air models.

5. Fill water trays to reach 45–55% humidity. Adjust the water surface area if needed.

6. Gather clean, fresh eggs. Avoid eggs with cracks or dirt.

7. Mark each egg with a pencil for easy tracking.

8. Place eggs in the incubator with the large end up or on their sides.

Tip: Let eggs warm to room temperature before placing them in the incubator. This helps prevent condensation and keeps humidity stable.

Daily Monitoring

You need to check your incubator every day to keep eggs healthy. Daily monitoring helps you spot problems early and adjust humidity or temperature as needed. Use this routine:

1. Read the digital hygrometer without opening the incubator. Keep humidity between 45–55% for the first 18 days.

2. Check the thermometer to make sure the incubator stays at the right temperature.

3. Weigh eggs every week to track weight loss. Eggs should lose about 12–14% by day 18.

4. Candle eggs on days 7, 14, and 18 to check air cell size and embryo growth.

5. Use a wet bulb thermometer if you want another way to measure humidity.

6. Add water to trays or sponges if humidity drops. Remove water if humidity gets too high.

7. Record all readings and changes in a notebook.

Note: Do not open the incubator unless you need to add water or check eggs. This keeps humidity and temperature steady.

Lockdown Checklist

Lockdown is the last three days before hatching. You must prepare your incubator and eggs for this important stage. Use this checklist:

• Stop turning eggs and remove the turner.

• Lay eggs flat or with the large end up.

• Raise humidity to 65–70% by adding warm water or damp sponges.

• Double-check your humidity gauge for accuracy.

• Fine-tune temperature and humidity settings before lockdown starts.

• Monitor humidity closely to prevent the shell membranes from drying out.

• Avoid opening the incubator unless you must add water.

• Watch for pipping and hatching signs.

Keep the incubator closed during lockdown. Stable humidity helps chicks hatch safely and reduces the risk of sticky chicks or dry membranes.

Post-Hatch Cleaning

After chicks hatch, you must clean your incubator. Cleaning stops germs and mold from hurting new eggs. Always take out eggshells, fluff, and leftover membrane. If you leave them, bacteria can grow. This can change humidity and harm future eggs.

First, unplug the incubator and let it cool. Remove trays, water pans, and all loose parts. Wash each part with warm water and mild soap. Scrub gently to get rid of dried egg bits. Rinse well so no soap stays. Dry each part with a towel or let them air dry. If parts stay wet, mold can grow and humidity can change.

Pay extra attention to the fan, heater, and sensor spots. Dust and fluff can block airflow. This can change temperature or humidity. Use a soft brush or cloth to clean these areas. If you have a digital sensor, wipe it gently. Check if it needs calibration. Clean sensors give better readings.

Disinfect the incubator with a safe cleaner. You can use diluted bleach or a special incubator cleaner. Rinse and dry all surfaces after disinfecting. Do not use strong chemicals that smell. Eggs can soak up bad smells and chemicals.

Look at water trays for white spots from hard water. Soak trays in vinegar and rinse well. Dry them before putting them back.

Here is a simple cleaning checklist for your incubator:

Tip: Let your incubator dry all the way before storing it. This keeps humidity steady and stops mold.

Clean your incubator after every hatch. Cleaning often helps eggs stay healthy and hatch better. If you hatch eggs a lot, set a reminder to clean before each batch.

�� A clean incubator helps you hatch strong chicks and keeps eggs safe every time.

You can hatch chicks well if you follow these steps. First, set the right humidity in your incubator and let it settle. Check humidity every day with a digital hygrometer. Keep the temperature steady at 99.5°F (37.5°C). Change humidity slowly so you do not stress the embryos. Watch egg weight-loss and air cell growth to adjust humidity. Raise humidity in the last days to help chicks hatch. Use checklists and guides to keep your hatch going well. For more help, look at the Incubation Troubleshooting Guide and humidity control articles.

FAQ

What should you do if chicks are sticky at 55% humidity?

Check egg weight-loss and air cell size. If eggs did not lose 11–13% by day 18, lower humidity next time. Sticky chicks often mean too much moisture stayed inside the egg. Use a digital scale and candle eggs to guide your adjustments.

How do you adjust humidity for dry or humid climates?

In dry climates, increase water surface or add wet sponges to raise humidity. In humid climates, use less water and open vents for more airflow. Always check your hygrometer and adjust based on egg weight-loss and air cell growth.

Does altitude or season affect incubator humidity?

Yes. High altitude or dry winter air can lower humidity. Warm, humid summers can raise it. Use a hygrometer to monitor conditions. Adjust water trays and ventilation as needed. Always track egg weight-loss to keep hatching steady.

How can you quickly restore humidity at lockdown without opening the lid often?

Add extra warm water trays or wet sponges before lockdown. Use a small tube or straw through a vent to add water without opening the lid. This keeps humidity high and stable for hatching chicks.

What is the best way to monitor egg weight-loss?

Weigh each egg before incubation. Weigh again on days 7, 14, and 18. Write down the numbers. Aim for 11–13% weight-loss by day 18. Use a digital scale for accuracy. Adjust humidity if eggs lose weight too fast or too slow.

How do you know if the air cell is the right size?

Candle eggs on days 7, 14, and 18. The air cell should grow larger each time. By day 18, it should fill about one-third of the egg. Compare with air cell charts for your egg type. Adjust humidity if the air cell is too big or too small.

Can you use household items to control humidity?

Yes. Use clean wet sponges to raise humidity. Place dry sponges or paper towels to lower it. Shallow dishes increase water surface. Silica gel packs help absorb extra moisture. Always check your readings after making changes.

Why should you avoid opening the incubator during hatching?

Opening the lid drops humidity and temperature fast. Chicks can get stuck in the shell or dry out. Only open the incubator if you must add water or help a chick in trouble. Use vents or tubes for small adjustments. When adding water through a tube, avoid dripping onto fans or electrical parts.