This will be my second self watering planter grow in a DIY SIP planter bed that I recently designed and finished testing with 8 cannabis plants. I planned on making a bunch of feminized seeds and although I did not succeed in making fem seeds my wicking bed did grow very nice plants.
DIY Self Watering Planter For Growing Cannabis
So here is a video shot on the first day of flower and I explain the system a bit for you. The system is very simple to build and very easy to maintain and run.
This build is in a 2 x 4 flood tray with a piece of 1/2 tubing running to the back of the tray. Water runs down the tray and into a 27 gallon reservoir. The inside of the flood tray is covered with seed trays that are then covered with polyester batting and the water level is set below the top of the trays. The water runs 24/7.
Check out my DIY Self Watering Planter Bed And Seed Project at http://420grower.org/diy-self-watering-planter-bed/ and watch the video to see how I built it.
I made a few changes along the way. The biggest change the second time around was adding a layer of panda film on top of the batting to prevent algae growth.
Why Use A Sub Irrigated Planter?
Every pot that is top watered has what is called a perched water table. It does not matter what size it is or what it is made from or what media is used. A perched water table is a layer of water that sits in your grow media. In simple terms it is a point where gravity and capillary action are equal. Water cant go up and cant move down. Usually it is at the bottom of your container.
Roots dont like to grow in this zone because there is little oxygen available there. This is also where root rot caused by pythium and phytophthora occur. Many people think adding gravel or something similar will eliminate this but that is not true.
What Is A Perched Water Table?
If you want more information on perched water tables in containers here are some excellent links for you:
http://www.pwk.resteddoginn.ca/soilmix.php and http://gardenprofessors.com/container-planting-intuition-vs-reality/
Although you can not eliminate it you can move it. By using a wick the reservoir beneath the pot becomes where the perched water table is. So wicking beds not only water the plant but also move the perched water table below the pots bottom.
If you want to grow healthy plants and put watering on autopilot then sub irrigated planters are the simplest way to do it. They actually used to be very popular in greenhouses but somehow after drip irrigation came along they were almost forgotten. Now growers who are tired of clogged emitters and tripping over tangled feed lines are rediscovering them.
Back To Basics
I have run several recirculating SIP grow and have run into a problem with pH continually dropping. While I can bring it back up it has been a challenge keeping it where I want it. I also had some issues with foxtailing and small bud size.
While I love to experiment and try new things I also need to be able to grow top quality bud. So I am putting my self watering planter project on hold for now. I am going back to basics in my new grow.
Many coco growers run a drain to waste system with top feed drip and that is also the recommended method from Canna for those who wish to automate the process. As I have no great desire to hand water that is what I will be doing.
Since I already have the drippers it will be an easy conversion and really the only difference is not reusing the nutes. Surprisingly with watering cycles are dialed in I will actually be using less nutes than by recirculating.
Follow My New HPS/DTW Grow
To see regular updates of this grow please go to my DO LEDS CAUSE FOXTAILING? post. I decided to place it there because I have changed my lighting in order to eliminate foxtailing.This seems like a priority to me. So I will be testing the change and updating my grow system.