Timers for Cannabis Grows

When growing cannabis indoors, you’re going to need timers for your indoor grow. You basically need to be your plants’ God, and give them sun when they need it and take it away when they don’t. Cannabis plants (not autoflowering strains) depend on light periods, which is basically the amount of time they get of light and darkness. Depending on the amount of hours of each, they’ll go through different stages; 18h of light and 6h of darkness for their growing phase, and an equal 12/12h period for the flowering or blooming phase. Of course, it’s practically impossible for you to control the times so rigorously, so you’re going to need to find a way around that.

To regulate your plants light period it’s important to acquire a timer. These devices are attached to the light switch and they’re in charge of turning the grow lights on and off when you’re not there, or even if you are there, you still won’t have to do it yourself. Not all timers are the same nor are they invincible, they all have a certain amp resistance, and when it comes to your crop you’ll need to be careful when picking the timer as a mistake in the timing or it breaking could ruin your entire grow.

Some people connect a power strip to an analogue timer, with three grow lights connected to the power strip and they expect the timer to not burn out. You mustn’t do this, as it can end up killing your plants, revegetating them or even setting fire to the room and causing the firemen and police to come investigating, and you definitely don’t want that. Some timers can deal with two lamps, but you can also get timer boxes that control the lights with total security. If you use one of the proper boxes, you can rest easy in knowing that nothing will go wrong and your crop should be fine if you leave it for a while.

Today we’re going to give you a list of different models of timers what how you can use them; some are used for specific things and not all of them can do the same.

Timer Models:

Timers for Cannabis GrowsAnalog Timer

These timers are the culprit of many problems in indoor grows. They work perfectly with just one 600W light or less, as well as working fine with water pumps, heaters for greenhouses or ventilation devices. It can be programmed in bouts of 15 minutes for 24 hours and it’s pretty easy to use through the switches; when they’re up they’re on and down means off, pretty simple, right? Some people think that they can use this timer with two lights, but if you try and do this you’ll soon notice that it stops working after a bit, although sometimes you can get lucky and they last longer but trust us when we say that it’s a very bad idea.

Timers for Cannabis GrowsDigital Timer

With this timer you’ll have more or less the same resistance to lights as the previous one. It will work perfectly with one light for years, but if you add another one it could end up breaking within weeks. This timer is extremely interesting for grows using CO2, irrigation systems, or hydroponics as you can program it by the minute and it has 8 on and off programs, as well as being able to program times for seven different days. What does all of this mean? It basically means that you will be able to precisely time your watering and other things down to the minute. You can choose which day of the week you want it to function, setting up certain times for Monday or the weekend etc. It’s a bit more complicated to use, but if you read the instructions it should be much easier to understand.

Legrand Timer

Timers for Cannabis Grows

This analog timer has the same switch function as the first one, you can program it in bouts of 15 minutes to turn on or off, although it has a much higher resistance in as far as amps. You can easily connect two 600W lights without worrying about it burning the place down or staying on all night accidentally or turning off out of the blue. It can also be used for ventilation systems and watering systems but we recommend using it with lights if you get this model. If you’re using a power strip, only connect two lights; supposedly it can work with three lights according to the technical details but honestly I don’t recommend using it with three maximum power lights for long periods of time; it’s better to play it safe and just use two.

GSE Timer with Various Inlets

Timers for Cannabis GrowsWith these kinds of timer boxes you can control the light period in your grow with four to twelve lights with just one timer. If anything goes wrong, the box itself is thermally protected so that it doesn’t catch fire. Safety is extremely important when you’re messing with this amount of wattage, and the automatic power down switch on your box will go off in case of emergencies. It spreads out the energy it consumes in various power inlets, so if you don’t have them both plugged in to an electricity outlet it won’t work. It works like this so that it doesn’t overheat and it can direct the power through two different inlets. There’s the normal model that can work with 4x600W, 6x600W, 8x600W and 12x600W, and the model that comes with a 2000W inlet for heating, as well as 4 inlets for 600w and 8 600w inlets. You can connect it to a relay to control the spreading of the light. Never use power strips with these kinds of timers or it might literally go pop.

So, now you have a little guide on what timers are and what each kind of model can do. Hopefully this has helped you to figure out which one you need for your indoor grow. Be careful when dealing with electricity, you don’t want the police and firemen to turn up at your door asking questions. Happy growing!

Author: Javier Chinesta
Translation: Ciara Murphy