Incubator Instructions (2025): Complete Step-By-Step Manual

If you’re searching for clear, do-this-now incubator instructions, this guide walks you through setup, temperature and humidity control, turning, candling, lockdown, hatch day, and post-hatch care. It also explains the critical difference between forced-air vs. still-air incubators and how to use the egg weight-loss method so your settings match real eggs—not just a number on a display.

This guide also covers a still air incubator workflow, so you can set temperature the right way even without a fan.

If you have not picked an incubator yet, you can use this egg incubator types guide to choose the right style before you follow the steps below.

Quick start (8 steps)

1. Place & preheat: stable room, away from drafts/sun; preheat 12–24h.
2. Temperature: Forced-air 99.5°F (37.5°C); Still-air 101–102°F (38.3–38.9°C) measured at egg-top height.
3. Humidity: track egg weight-loss (≈ 11–13% by lockdown; ≈ 13–15% total).
4. Load: warm eggs to room temp; pointy end down; mark shells X/O.
5. Turn: 3–5× daily (auto turner preferred).
6. Candle: Day 7 / 14 / 18 (chicken timeline).
7. Lockdown: from Day 18; stop turning; raise RH to ≈65–75%; avoid lid opening.
8. Hatch & clean: move chicks to brooder (90–95°F first week); clean, disinfect, dry incubator.

1) Placement, Preheat & Calibration

Placement: solid, level surface; avoid windows, vents, and high-traffic doors.

Preheat: run the incubator empty 12–24 hours to stabilize.

Calibration: cross-check with two thermometers and a hygrometer at egg height; note the reading you’ll trust through the hatch.

Helpful gear: a 0.1 g scale for weight-loss tracking, a bright candler, and a notebook or spreadsheet.

Ready to hatch quail or small birds? See our quail egg incubator lineup for capacity and feature options matched to tiny eggs.

2) Temperature Instructions: Forced-Air vs. Still-Air

Why it matters: still-air cabinets stratify heat (hotter higher up). To keep the embryo at the right temperature, you must aim higher at the egg-top in still-air units.

• Forced-air incubator: set 99.5°F (37.5°C); measure anywhere reasonable near egg height.
• Still-air incubator: set 101–102°F (38.3–38.9°C); measure at egg-top height.
• Adjustment cadence: make small changes, then wait 1–2 hours to let thermal inertia settle before judging.

Which is better: forced convection or natural convection?

A forced-convection (forced-air) incubator is usually better for most beginners because the fan keeps temperature more even across the eggs.
A natural-convection (still-air) incubator can still hatch well, but it needs more careful thermometer placement and small, patient adjustments.

Still air incubator model 2100: quick temperature rule

If your manual calls your unit a still air incubator model 2100, treat it as a still-air (natural-convection) incubator.
You should measure temperature at the top of the eggs, not at the floor or lid.
You should aim for 101–102°F (38.3–38.9°C) at egg-top height because still air forms a warm-to-cool vertical layer.
You should change settings in tiny steps and then wait 1–2 hours before you judge the result.

Want an easy, stable workflow? Our Automatic Egg Incubator 3 Trays for Birds and Quail provides forced-air circulation and auto turning so beginners can focus on observation instead of babysitting knobs.

3) Humidity Instructions: Use the Egg Weight-Loss Method

Instead of chasing a fixed RH number (which varies with climate, shell porosity, and room conditions), track weight-loss:

1. Weigh each egg on set day; record the grams.
2. Targets: by lockdown, total loss ≈ 11–13%; full-term loss ≈ 13–15%.
3. Checkpoints: re-weigh at Day 7 / 14 / 18 (chicken).
4. If loss is low (air cell too small): reduce RH / increase ventilation / reduce water surface.
5. If loss is high (air cell too big): increase RH / reduce ventilation / add sponge or surface area.

No scale today? Use 35–45% RH as a starting range for days 1–18, then 65–75% RH for hatch—but switch to weight-loss tracking as soon as you can for steadier outcomes.

4) Turning & Candling

• Turning: 3–5×/day (or use an automatic turner); keep total swing ~90–180°. Mark shells X/O to confirm each pass.
• Candling (chicken): Day 7 remove clears/blood rings; Day 14 verify air cell growth; Day 18 final check then lock down.

5) Lockdown & Hatch Day

• Timing (chicken): start lockdown Day 18 (other species ≈ last 3 days).
• Settings: stop turning; raise humidity to ≈65–75%; minimize lid openings.
• Progress: internal pip → external pip → “zip” → hatch; this can take 12–24+ hours—patience beats risky assists.
• Brooder: move dry chicks to a brooder at 90–95°F for Week 1, then reduce ~5°F per week.

6) Ventilation & “Open-Lid” Discipline

As embryos grow, oxygen demand rises—open vents gradually.

Eggs need ventilation because the shell has tiny pores.
Those pores let oxygen move in and carbon dioxide move out as the embryo grows.
Those pores also let water vapor slowly leave the egg, which is why the air cell gets bigger over time.
Vent settings and humidity work together, so you should open vents gradually while you track air-cell growth or egg weight-loss.

If you must add water, use a syringe/tube through a vent so you don’t dump heat and humidity. Keep any lid opens short, infrequent, and purposeful.

7) Cleaning & Biosecurity

After hatch and cool-down, remove trays and water pans, wash with mild detergent, disinfect, and air-dry. Before the next batch, run the unit empty for 1–2 hours to ensure no odors or residues remain.

8) Troubleshooting Quick Map

• Early hatch, navel issues → likely too hot → confirm probe at egg-top (still-air), reduce setpoint slightly.
• Late hatch, weak chicks → likely too cool → increase 0.2–0.3°F and re-check in 1–2 hours.
• Shrink-wrap at hatch → humidity too low (often during lockdown) → increase RH, reduce ventilation, add sponge/surface.
• Over-large air cells, undersized chicks → over-evaporation earlier → raise RH sooner next time.
• Batch inconsistency → shell porosity mix → rely on weight-loss per batch, not a one-size RH.

9) Timelines & Targets (Chicken Example)

*Measure still-air temperature at egg-top height.

10) Related Reading (internal blog links)

• Deep dive on placement, preheat, and routine checks: small egg incubator setup.
• Dialing in climate for tiny eggs: quail incubator temperature and humidity guide.

11) Print-Friendly Checklist

• Preheat 12–24h; double-check sensors at egg height
• Forced-air 99.5°F; still-air 101–102°F (measure at egg-top)
• Track weight-loss; aim 11–13% by Day 18 (chicken)
• Turn 3–5× daily; mark X/O; auto turner OK
• Candle Day 7/14/18; remove clears/quitters
• Lockdown Day 18; 65–75% RH; avoid lid opening
• Move dry chicks to brooder at 90–95°F; clean & disinfect incubator

Final tip

If you’re primarily hatching quail, browse our curated quail egg incubator collection, and consider the Automatic Egg Incubator 3 Trays for Birds and Quail for simpler day-to-day operation and steadier conditions.

FAQ: Operating Your Egg Incubator

How do I calibrate an incubator's thermometer and hygrometer accurately?
Your incubator is only as good as its sensors. Take time to calibrate before you set any eggs.
For temperature:
- Place a reliable digital thermometer at egg height inside the incubator.
- Run the incubator empty for 1–2 hours so the reading is stable.
- Compare the incubator display to the thermometer.
- If the incubator reads 100.5°F but the trusted thermometer reads 99.5°F, remember there is a 1°F difference.
- Adjust the setpoint or write down the “true” temperature so you always read it correctly.
For humidity:
- Use two hygrometers if you can, and place them near egg height.
- Run the incubator for at least 1–2 hours.
- Most good hygrometers will match within about 2–3% RH.
- If one is always higher or lower, trust the one that agrees with your egg weight-loss or air-cell growth.

How does an automatic egg turner work and is it necessary?
An automatic egg turner tilts or rolls the eggs for you. A small motor moves the tray a little bit every few hours so the eggs slowly change angle.
This movement:
- Keeps the yolk centered.
- Stops the embryo from sticking to one side.
- Helps blood vessels grow evenly.
Is it necessary? Not always.
- You can turn eggs by hand 3–5 times per day if you are home and very consistent.
- An automatic turner is strongly recommended for beginners, busy owners, or classrooms.
- It lowers the risk of missed turns and sudden drops or bumps.
If you use an automatic turner, make sure it is level, moves smoothly, and stops turning at lockdown.

What is the ideal temperature and humidity for different types of eggs in an incubator?
There is no single perfect setting for every species, but there are safe starting points.
For chicken eggs in a forced-air incubator:
- Temperature: about 99.5°F (37.5°C) at egg height.
- Humidity: about 35–45% RH for Days 1–18, then 65–75% RH at lockdown and hatch.
For a still-air incubator:
- Measure at the top of the eggs.
- Temperature: about 101–102°F (38.3–38.9°C) at egg-top height.
- Use the same basic humidity strategy, then adjust based on air-cell growth or egg weight-loss.
Duck, goose, quail, and other species use very similar temperatures but often need slightly different humidity and timelines.

Why is proper ventilation important in an incubator?
Growing embryos need fresh air just like chicks and adult birds.
Good ventilation:
- Brings in oxygen.
- Lets carbon dioxide and extra moisture leave.
- Helps keep temperature and humidity even across the whole incubator.
Poor ventilation can cause:
- Weak or late chicks.
- Sticky chicks from trapped moisture.
- Overheating in some spots and cool areas in others.
Keep vents at least partly open during the whole hatch. Open them more as embryos grow, especially after Day 18, so the chicks can breathe easily.

Why do eggs need to be turned regularly in an incubator?
Turning copies what a broody hen does all day.
Regular turning:
- Stops the embryo from sticking to one side of the shell.
- Keeps the yolk and embryo centered.
- Helps blood vessels spread evenly around the egg.
- Supports normal organ and limb development.
If you do not turn the eggs, or you turn them very little:
- Embryos can stick to the shell membranes.
- Chicks can develop deformities or die before hatch.