Do you also sell a ready-to-use growbox?

Yes, we offer a complete set in our shop.

You can order the set here:
Complete Fridge Grow Set – All you need for the conversion

Can I use any fridge?

As long as it’s still working – yes. We do, however, recommend a size between 1.2 and 2 meters, as smaller devices usually have insufficient cooling power. When choosing a fridge make sure to pick one without any extra features, like a freezer section or auto-deiceing, as those only interfere with the process.

How can plants even survive in a sealed system?

Most people mistakenly assume that plants require fresh air to survive and therefore cannot survive in a sealed system.
However, plants essentially have only two requirements of their surrounding air:

  • CO2 has to be available.
    Our controller is actively controlling the CO2 level inside your box, replenishing CO2 as it gets used up by the plants. You can even set a CO2 level higher than the atmospheric one, allowing you to further boost your plants growth.
  • Plants need to be able to evaporate water.
    In order to take on nutrients from the soil, plants need to be able to evaporate water via their leaves. This causes a rise in humidity, which is constantly measured by our controller. The fridge is then turned on, condensing the water and keeping humidity in an optimal range.

Isn't there a high risk of mold?


Humidity is actively controlled in our system and constantly kept in the optimal range. As temperature and humidity can be controlled independently from each other you can even slowly dry plants over a long period of time at very low temperatures and humidity without the risk of mold.

Won't this system use a lot of power?

Power consumption of our system is around the same as conventional grow systems. While the power usage of the lamp stays the same, our system needs some additional power to run the fridge, but doesn’t require a power hungry filter system.

Why do my lights turn off during the day?

Your light is being turned off by our controller to prevent overhearing of your grow box. This can have several reasons:

  • Your plants are still too small.
    Because the fridge is primarily being used as a dehumidifier, it only turns on when there is enough humidity in the air. Small plants only evaporate very little water, so the fridge hardly ever runs and is not able to remove the heat generated by your lamp.
  • Your heater is too strong.
    If your lamp typically turns off directly after your heater has turned on and off again (watch your graphs), then your heater is most likely just too powerful and causes temperature spikes. Try to reduce your heaters power in the expert section on the settings page, or switch to a less powerful one.
  • Your lamps are too strong.
    A typical household fridge can cope with around 100W of lamp power. If you want to use more, you will have to pick a stronger fridge.

And what do I do now?

First of all: don’t worry. While plants are pretty sensitive to disturbances during the night cycle, small gaps during the day won’t matter.

If your plants are still very small (seedlings, clippings) we recommend you use “Greenhouse Mode”. To do so go to the general settings and choose the preset “Greenhouse Mode”, or choose control mode “Temperature only” when using custom settings.
Be aware that his mode completely ignores Humidity. You need to put your plants in a plastic greenhouse or they will dry out!


I can't find the wifi network of my controller!

Please try the following steps:

  1. Ensure your controller has fully booted.
    The LEDs on your controller should show solid green or solid yellow. If they are still running in a circle, your controller is still booting. Be aware that the boot process can take up to 10 minutes, especially if the controller was just updated.
  2. Try to reboot your controller.
    Plug out the USB supple and wait for 10 seconds, then plug it back in. Once your controller has rebooted try to find the network again.
  3. Try to reset your controller to factory defaults.
    Press and hold the button in the top of the controller’s case until all LEDs have switched from blue to yellow. Wait until it has rebooted, then retry.

How can I reset the controller?

To reset the controller to factory settings , you have to hold down
the button in the middle until all LEDs light up continuously yellow
(the controller must not be booting or updating)


Controller reset

When all LEDs have switched to yellow, the controller has been
successfully reset.

I'm connected to my controller's wifi network but it's not detected by the app!

Many smartphones popup the warning message “This network has no internet access”. Make sure you have confirmed this message!

If you do not confirm this message, your smartphone won’t fully connect to the wifi network and our app won’t be able to work.
Sometimes it takes a few seconds for this message to show up, so stay in your wifi settings page until it shows.

If that does not solve the problem, you can also try to activated airplane mode before you connect to the wifi network.

Should you still be unable to detect our controller, please try a manual connection by checking “advanced” on the connection page and entering the IP address

How do I connect via remote access to TOR hidden service? 🎥

Want to check your plants from anywhere in the world in a secure and anonymous way? #FridgeGrow uses the hidden service TOR to give you 24/7 remote access with high security for your data. Check your webcam, graphs, data or change any settings from anywhere. Don’t worry about your data, TOR is a secure way to access your FridgeGrow controller. No cloud or servers for your data – just you and your controller.

You can watch a video tutorial in the following:


How can I download the system diagnostics? + video tutorial 🎥

In the following you can watch a video tutorial:



How often do I really have to water?

Obviously, that strongly depends on your setup, especially the size of your pots and plants. Generally speaking though, you can assume that you will need roughly 1/10th than you normally would for plants of the same size.

Be aware though that this increases the risk of over watering!

Always check the weight of your pots. Your soil should never be completely wet, just a bit moist. When in doubt stay on the dry side, it’s no problem if the first 1 – 2 cm of your solid dries out.

Which medium and fertilizer should I use?

In general you can use any medium and fertilizer you want.

Especially for beginners, we recommend the usage of soil in combination with solid fertilizers though. Liquid fertilizers can be a bit tricky to dose correctly, as the amount of water needed in our system is drastically lower than in conventional systems. Solid fertilizer, which can simply be added to the solid, is therefore optimal as it is independent of watering.

Why does the CO2 level rise during the night?

That’s a completely natural phenomenon. At night your plants are using up the sugar they created during the day using photosynthesis. This sugar is essentially digested using oxygen, creating co2 in the process.

Your soil can also contribute to the rising co2 level. Especially when biological fertilizers are used, bacterial processes in the soil can create a lot of co2. Sometimes you can even see a rise in co2 levels during the day, directly after adding fertilizer.

What does the fourth sensor reading mean?

That reading is the “vapor pressure deficit”, short VPD.

VPD is a value that gets calculated from temperature and humidity, not an actual sensor. This value describes how easily water can evaporate in your system and is used by several growers as an indicator on how suitable the environment is for plants. You don’t have to work with this value though, using temperature and humidity directly works just as fine.

Whats the percentage value under the light symbol?

This value shows how much of the day cycle your lights are actually turned on. A value less than 100% indicates that your controller has to turn off your lamps in order to prevent your system from overheating.

Values between 80 and 100% are usually perfectly acceptable. If your value is below that you may need to change your setup a bit or try different settings.

You can find additional information on this topic here in the FAQ section under the question “Why to my light turn off during the day”