Grow Room too Cold? Here Are Hacks That Actually Work!

Cold temperature can kill plants. Particularly indoor grow plants where ‘The Mother Nature’ is not there to deal with them. Also, you as a grower should be aware of it. 

Anyway, what are the hazards when your grow room is excessively cold? To be precise, a fall in temperature causes damage to the leaves and roots, leading to less germination and less yield in the long run. 

None of us growers needs that, isn’t it?

To manage the cooling issue, you must have bought a radiator or rolled out a couple of changes to the growing system. Yet, it is excessively cold while the lights are off, especially if your tent is placed in a disengaged room. 

Nonetheless, we have been worried about this very issue for a long time now. Hence, to help our fellow growers with the same, we have got an article that will guide you in maintaining a healthy temperature for your grow room. 

How Cold is ‘Very Cold’ for A Grow Room or Tent? 

Grow tent temperature never remains the same throughout the day. It is bound to have a cycling temperature increase and decrease during day and night. For both hot-season harvests and cool-season crops, there are different expectations for this temperature limit. 

It is great for Warm Season Crops to have a daytime high of mid 70 degrees, and the evening temperature is usually lower than 60 degrees. For Cool Seasoned Crops, day and evening time limits should be set at 60 and 50 degrees, respectively.

Now, getting to the main point, how to keep an eye on the grow room’s temperature. When you open the tent to check the temperature would cool the plants, use something that screens it for you in a remote manner. 

The smart idea is to use a Min-Max Thermometer. It calculates the maximum delta/outlet temperature for recent hours and displays that. A move up to that would be a Remote Outdoor Thermometer, which does the same work just with a wireless connection.

Grow Room Too Cold Symptoms 

Setting a thermometer and recognizing the best suitable temperature range is ideal for identifying a ‘too cold’ grow area. Aside from that, check for these after indications also. 

Small or Weak Growth. 

Humid regions and undesirable mold. 

Chilled root systems (Hydroponics). 

Awful taste, smell, color, or density of growing plants.

Issues Due To A Cold Grow Room 

Among the plenty of issues that a ‘too cold’ grow room can suffer from, we have discussed a few of them in detail below.

Low Germination 

Most grow plants sprouts well at a temperature of 65 to 75 degrees Fahrenheit. Some warm-season flowers and vegetables like this reach to be 80+ degrees. Be that as it may, with a grow tent cooler than 60 degrees, you can not expect that the plants should even start the course of germination. In the long run, they are leading to low and a very poor yield.

Higher Oxygen Concentration 

A lower temperature of your grow space will cool the water, prompting a higher concentration of oxygen dissolved in it. While plants intake that through roots, it thwarts the digestion and enzymic cycles of plants. 

Placing the Exhaust Fan into Timer 

For the sake of appropriate ventilation, you should keep a few intake and extraction fans turned on. Typically, that is no issue as you have inward heating sources like grow lights and radiators. In any case, imagine a scenario where the lights are switched off. Should the extractor fan be turned off to trap the heat inside? 

No. Be that as it may, one must attempt to lower the fan speed. Connecting the extractor fan of your setup with a Day/Night Fan Speed Controller is the ideal choice here. When you put forth the temperature limits of day and night, they will control the speed, depending on whether the lights are on or off.

A Moist And Unhealthy Grow System 

The low temperature might cause a couple of cold or problem areas to spring up in certain spots of the grow space. It ultimately establishes a moist climate and undesirable shape. Both of the issues might leave your plants with serious damage and over-purpling leaves.

Fool-Proof Hacks to Deal Wih A Cold Grow Space 

Now, let us take a glance at the more brilliant piece of the article. From here, we will talk about certain hacks and solutions for raising the temperature to a suitable level. 

Yet, before you choose to spend any money to address the low-temp issue, consider these couple of hacks that may lead to an exit from it-

Insulate As Much As Possible 

You might already be managing cold temperature within your grow room. Also, an ideal way to get it going is to insulate the space however much as could reasonably be expected. In this way, you never need the heat to fly away as it reaches the plants and supplements. 

Now, protecting a grow space does not simply mean filtering the wind flow. Here is a proper list of insulation works you need to do- 

In case you are growing in pots, fold Aluminum Foil Sheets over them. 

On the off chance that the pots are in direct contact with the cold floor, put a Polystyrene Plastic Sheet in the middle. 

Wrap the entire grow tent from outside, leaving about no chance for the heat to take off.

Keep Lights On Rather Than of Plugging In A Heater 

Suppose your plants are in the vegetative stage or not sensitive to photoperiods. You don’t actually need to keep a radiator connected to manage the cold wave in the two cases. All things being equal, it’s smarter to use however many grow lights as could reasonably be expected. 

Now, you might raise an eyebrow on running grow lights for 24 hours every day. However, it actually will cost less power than even 5-6 hours of radiator runtime. Also, some power supplying companies give less expensive power during the evening. 

Improve the Air Circulation in Grow Room

You are going to generate more heat inside the growing area effectively. In any case, consider the possibility that the heat does not reach the plants and winds up, making hotspots, all things being equal. 

Make a point to channel the warmth around the whole space. A few radiators think of circulation techniques for their own, similar to a fan. Be that as it may, you will have to circulate them inside for a considerable lot of them. An ideal way is to use a reserve fan.

Transform Composts Into Heat Sources 

It might sound peculiar; however, we discuss a strategy that heats the manures and transforms them into heat sinks. As your tent will probably be cool in the evening time, putting away some heat within the fertilizer heaps is a good thought. 

The process is basic. Make a filter in a place that is warm during the daytime. Allow the daylight to warm up the fertilizer heaps, and they will deliver the heat later in the evening. Simply pick the spot of heating fertilizers cautiously.

Take The Air Intake Using A Warmer Space 

A reason for a low temperature is the absence of warm intake air. Moreover, that is on the grounds that the intake air is imported from a place that is not really hotter than grow space itself. Trying to address the issue might raise the base temperature of your grow room. 

Improve The Nutrient’s Heater by 20 Percent 

You may be experiencing a chilled-up grow space, yet also chilled-up supplement solutions. The damage that a cold supplement solution can cause to your plant is extreme. 

As an answer, you might have a go at increasing the supplement strength by 20 percent(or so), so the plants may allow the essential supplements without as little water as could be possible. Mostly, the impacts of low temperature on the plant’s health will be minified to a great extent. 

PS: Remember, plants transpire less in a chilled environment. So commercial growers might need to make up for increasing the supplement strength.

Best Heat Sources for Your Grow Space 

The most popular, and potentially the most effective one, on the off chance that you have not got one yet. From an expansive perspective, we can divide all electric heaters based on the size of the growing area- 

  • Electric heaters for Grow Room.
  • Electric heaters for Grow Tent.

Size and Heating Power 

Where heaters for grow rooms are bigger in size and weight, heaters for tents are lighter and smaller. The power (in terms of Watt) exists in 1500-2000W for room heaters and 750-1500W for tent heaters. 


You might have to run the heater for specific hours in a day, generally dependent on the light schedule. For an 18/6 or 16/8 light cycle, small-sized heaters will do great with the 8 hours of continuous runtime. The bigger ones are more fit for grow rooms, where you might have to run them for even 24 hours.

Oil Filled versus Ceramic 

It is another significant distinction that might impact your buying behavior. A basic explanation of oil-filled versus ceramic heaters is-it is the heat generation medium that is important. If there is an occurrence of an oil-filled one, the balances are topped off with heated up oils, producing radiant heat. Also, on account of ceramic heaters, ceramic is the heating material that generates brilliant convection heat. 

It is another significant distinction that might impact your buying behavior. A basic explanation of oil-filled versus ceramic heaters is-it is the heat generation medium that is important. If there is an occurrence of an oil-filled one, the balances are topped off with heated up oils, producing radiant heat. Also, on account of ceramic heaters, ceramic is the heating material that generates radiant convection heat. 

On the off chance that you do not have one, it is very well recommended to deal with the heating problem. However, keep the expenses in your mind before getting one.

Grow Tent Tube Heaters 

A tubular heater is the best and most simple heating solution of every one of the available choices on the market. It consumes a couple of watts of power(90-200W) and is ideal for growing spaces with small foot space. 

Best tube heaters in the market accompany various useful elements like A security cut out, Overheating prevention, added on movable legs, and so on. For bigger space, more than such heaters might be required. 

Be that as it may, the most epic place to put a tube heater is on the floor rather than on the growing tray. All things considered, you need to raise the plate level a smidgen by putting some empty pots as help.

At any rate, ensure that there is sufficient wind current to spread the heat around the bottom. It will heat up the substrate and root system that support better yield. 

You can also use a temperature-controlled programmable extractor fan that will work depending on the temperature for the best outcomes.

Heating/Cooling Mini Splits 

If you live in a continental climate zone, you know it is too cold in winter and too sweltering in summer. You face a temperature drop and will experience the ill effects of a too warm issue in summer. In the end, you have to spend after both cooling and heating solutions. 

Let us combine them? We are discussing a Heating/Cooling Mini Split that you might already know. It contains one indoor and one outdoor unit and offers a wide range of BTU. Ordinarily, a decent heating/cooling mini-split can offer a wide range of both heating and cooling.

You may be agonizing over the cost and energy cost. Unfortunately, these units are pretty expensive. Be that as it may, if you are a shrewd purchaser, your model may give you 30 to 50 energy savings.

Soil Mats 

At whatever point there is an issue like chilled grow space, most growers focus on heating the air inside it. However, one of the main activities is to heat the soil/cultivating, all things considered. 

These mats work with a mission to keep the soil temperature between 75 to 85°F. Essentially, which is far more expensive to obtain by heating the air. 

Certain people use just these mats as germination mats. Try not to be tricked by that, in light of the fact that these mats are incredible to heat soils even after the germination stage.

Aquarium Heater: To Warm Up The Nutrients 

Cold roots are perhaps the biggest danger for any grower, particularly who grows in a media-less system. What we refer to by media-less systems are-NFT(), DWX(), Aeroponics, and so forth.

Why? All things considered, these sorts of plants come up short on the insulation that growing media like soil can give. 

The solution is very simple. Heat up the nutrients solution externally. An amazing device to do that is the Aquarium radiator. One such radiator can definitely raise the temperature to 70+ degrees Fahrenheit.

Water Storage 

As we discussed earlier, transforming soil composts into heat, putting away manures heaps and works wonders. We are looking at executing a similar idea with a barrel of water. 

To build this heatsink, use a 55-gallon barrel or any water storage tool of your preference. Place the compartment in a space where the sunlight can warm it. Later on, place it inside the grow room and let the water release heat energy. Thus, a properly sized water barrel will battle against cold temperature for very few hours. 

For a better outcome, use a dark container for maximum heat absorption.

We hope this article helps you in the best way possible with regards to maintaining a proper grow room temperature.

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