• Growing with an 18 hour Day/Night Cycle
• Recommended Irrigation Cycles
• Intelli-Cycle Brochures

The theory behind the 18 hour Day/Night cycle is that during a normal 24 hour light cycle plants will usually acheive high growth rates peaking at 100% capacity during the first 50 - 60% of the day. The growth rates will then diminish rapidly and the last 20 - 30% of the day acheives minimal growth. So by reducing the length of the day we are triggering an increased growth mode where the growth rates are at their peak for the majority of the day. This effectively achieves a very fast growth cycle with full yield potential.

NOTE: To achieve these incredible growth rates it is important to provide maximum light intensities and CO2 enriched conditions. The recommended lighting is 600W per square metre.

The growth acheived during an 18 hour cycle can be the equivalent to that acheived during a 24 hour cycle. So by running 18 hour cycles the same growth and yield can be acheived in 75% of the time.

Reduced day lengths also mean reduced power consumption. Grow more and use less power. Who can argue with that?

For example, an average crop grown from seed using a 24 hour day/night cycle will have a 4 weeks grow cycle and an 8 weeks flower cycle. This equates to 28 days @ 18 hours a day and 56 days @ 12 hours a day = 1176 hours of light over 12 weeks.

An accellerated crop using an 18 hour day/night cycle will achieve the same yields using a 3 week grow cycle and a 6 week flower cycle. This equates to 21 days @ 14 hours a day and 42 days @ 6 hours a day = 546 hours of light over 9 weeks resulting in a 40% reduction in power consumption and a 25% reduction in crop time.

The recommendations below are just guidelines for you. The main point here is that regardless of the system or the growing medium, the standard 15 minute irrigation cycle is usually a lot more than your garden needs. Every system will be different and irrigation times will vary depending on the container size, ie size of pot, tray, basket etc and how hot the growroom is and how big the plants are. The irrigation method will also vary the irrigation time and it is advisable to monitor your system regularly when applying new irrigation times to make sure the plants are being watered enough. Irrigation Cycles may also need to be varied as plants get bigger and start to drink more.

For other growing mediums not listed below, select one of the 3 growing mediums below that have similar characteristics to your growing medium and follow the instructions. Perlite has average drainage and average moisture retention and is similar to pumice and other small particled gravels etc. Expanded Clay has high drainage and low moisture retention and is similar to river pebbles and other large particled gravels etc. Coco has low drainage and high moisture retention and is similar to some rockwools and other fine growing mediums that hold a lot of moisture etc.

Drip System - Recycling
Perlite is usually only used in hand watered systems or drip systems. The ideal irrigation cycle for perlite in a drip system will depend on container size. To ascertain the best "On Time" manually turn on your pump and time how long until the solution starts draining from the bottom of the growing container. Add 2 minutes to this time and program your Intelli-Cycle to turn On for this amount. Perlite has medium moisture holding capacity and will require repeat irrigations approximately every 1 to 2 hours depending on the container size (small containers will need watering more often), and how hot the growroom is. Subtract the "On Time" from the desired cycle and program the Intelli-Cycle to turn Off for this amount of time. During warmer months the cycles can be the same 24 hours a day but during the cooler months the plants will not need watering as often during the dark period. In this case set the Intelli-Cycle to use the Light Sensor. Set the "On Time" the same for both Light and Dark. Set the Cycle in the dark to be twice that in the light. ie if you have a 1 hour cycle in the light, set a 2 hour cycle in the dark. Subtract the "On Time" from the doubled cycle time and program the Intelli-Cycle to be Off in the dark for this time.

Drip System - Run To Waste
It is more important to monitor and vary the irrigation time of Run To Waste systems as the plants grow. Watering too much will be a waste of nutrient solution. The desired amount of "Run-Off" from a Run To waste system is 10%. ie if it takes 10 litres of water before there is any run off, then you will need to water an extra 10% = 1 litre. You will need to time how long this takes every couple of weeks and adjust the Intelli-Cycle to suit. The length of Cycle will be every 1 to 2 hours, and can be doubled in the dark as explained in the Perlite - Recycling information.

Drip System - Recycling
Expanded Clay is a very versatile growing medium and can be used in just about any hydroponic systems. The ideal irrigation cycle for expanded clay in a drip system will depend on container size. To ascertain the best "On Time" manually turn on your pump and time how long until the solution starts draining from the bottom of the growing container. This will usually happen very quickly as expanded clay drains very well. Double this time and program your Intelli-Cycle to turn On for this amount. Expanded Clay has a low moisture holding capacity and will require repeat irrigations approximately every 1/2 to 1 hour depending on the container size (small containers will need watering more often), and how hot the growroom is. Subtract the "On Time" from the desired cycle and program the Intelli-Cycle to turn Off for this amount of time. During warmer months the cycles can be the same 24 hours a day but during the cooler months the plants will not need watering as often during the dark period. In this case set the Intelli-Cycle to use the Light Sensor. Set the "On Time" the same for both Light and Dark. Set the Cycle in the dark to be twice that in the light. ie if you have a 1/2 hour cycle in the light, set a 1 hour cycle in the dark. Subtract the "On Time" from the doubled cycle time and program the Intelli-Cycle to be Off in the dark for this time.

Flood and Drain System
In a Flood and Drain system the growing medium is well watered very quickly as the growing containers are flooded. There is no need to double the irrigation time as we did with the drip system. Turn on the pump manually and time how long it takes to flood the growing container till the solution starts overflowing back to the reservoir. Add 30 seconds to this time and program the Intelli-Cycle to turn On for this amount. As container sizes in Flood and Drain systems are usually quite large the cycle only needs to be every 1 to 2 hours. Subtract the "On Time" from the desired cycle and program the Intelli-Cycle to turn Off for this amount of time. During warmer months the cycles can be the same 24 hours a day but during the cooler months the plants will not need watering as often during the dark period. In this case set the Intelli-Cycle to use the Light Sensor. Set the "On Time" the same for both Light and Dark. Set the Cycle in the dark to be twice that in the light. ie if you have a 1 hour cycle in the light, set a 2 hour cycle in the dark. Subtract the "On Time" from the doubled cycle time and program the Intelli-Cycle to be Off in the dark for this time.

Aeroponics System
Aeroponic Systems usually only have a small amount of expanded clay growing medium in baskets as a support medium. The bulk of the plants roots will hang below the baskets and are misted with nutrient solution on a regular basis. As the roots will dry out fairly quickly the cycles will need to be short and regular. There are a few things that may vary the time but an average cycle for an Aeroponic System will be 2 minutes On and 3 minutes Off. The Intelli-Cycle is perfect for this type of system as very few other timers can switch in cycles like this. During warmer months the cycles can be the same 24 hours a day but during the cooler months the plants will not need watering as often during the dark period. In this case set the Intelli-Cycle to use the Light Sensor. Set the "On Time" the same for both Light and Dark, ie 2 minutes. Set the Cycle in the dark to be twice that in the light. ie 6 minutes.

Drip System - Recycling
Coco is usually only used in hand watered systems or drip systems. The ideal irrigation cycle for coco in a drip system will depend on container size. To ascertain the best "On Time" manually turn on your pump and time how long until the solution starts draining from the bottom of the growing container. Record this time and turn the pump off, the coco will continue to drain for some time after this. Because of this you do not need to water much more than the time you recorded. Add 10 to 15 seconds to this time and program your Intelli-Cycle to turn On for this amount. Coco has high moisture holding capacity and will require repeat irrigations approximately every 2 to 4 hours depending on the container size (small containers will need watering more often), and how hot the growroom is. Subtract the "On Time" from the desired cycle and program the Intelli-Cycle to turn Off for this amount of time.

As coco holds a lot of moisture there are no irrigation cycles required during the dark period. The easiest way to achieve this with the Intelli-Cycle is to program it so that it does not use the Light Sensor and plug the Intelli-Cycle in with your light timeswitch so it only turns on when the lights are on.

Drip System - Run To Waste
It is more important to monitor and vary the irrigation time of Run To Waste systems as the plants grow. Watering too much will be a waste of nutrient solution. The desired amount of "Run-Off" from a Run To waste system is 10%. ie if it takes 10 litres of water before there is any run off, then you will need to water an extra 10% = 1 litre. You will need to time how long this takes every couple of weeks and adjust the Intelli-Cycle to suit. The length of Cycle will be every 2 to 4 hours, and can be doubled in the dark as explained in the Coco - Recycling information.

As coco holds a lot of moisture there are no irrigation cycles required during the dark period. The easiest way to achieve this with the Intelli-Cycle is to program it so that it does not use the Light Sensor and plug the Intelli-Cycle in with your light timeswitch so it only turns on when the lights are on.