Fenderbender
Well-Known Member
But my point is the roots you get at the bottom of a sip are not using that oxygen as they are incapable of it. As that's the switchover that happens when you plant into a SIP roots change to aquatic roots.When I designed my Triforce SIP, I studied up on oxygen permeation into soil, and the need for roots to have access to oxygen—what is called "root respiration". This is necessary for the biochemical processes that create the cellular energy that drives both water and nutrient uptake in the roots. In other words, roots love oxygen. If they don't get enough, because the soil is impervious to air, or because of too much water in the soil, this shuts down growth and also invites disease due to the anaerobic environment.
So in my design I maximized the surface area of the air-to-soil interface, by putting a lot of small holes in the domes, both on the top and on the sides. I call these the "air/water vents". The holes have a dual-dual purpose—air inflow/outflow and water inflow/outflow. As the reservoir level goes down, more holes provide air to the root zone. When the reservoir is filled down the tube, the water level in the domes rises, pushing air into the medium.
Another very important dynamic is the composition of the soil medium, which must accommodate good air flow. This is why it's very good to use lots of coconut coir, and a good amount of perlite as well. Keep in mind that on the microscopic level, the soil medium has lots of air space between the solid particles. The root filaments inhabit these spaces where they have plenty of access to oxygen.
More photos and details about my design HERE.
The heart of the Triforce SIP—three domes D1, D2, and D3. Note that there's a friction fit on the fill tube connection to D1, so that it can hover in place in the air pocket. When the bucket is filled with soil and in use, the fill tube can be adjusted slightly up or down no problem.
#2 food grade HDPE plastic yogurt container.
The shaded area is what I call the "R zone", where roots have access to the saturated medium in the reservoir, and also have access to the air vents. This R zone is much larger than in other SIP bucket designs, and provides a large wicking area as well.
So far, so good...
A CBD clone recently transferred to the flower house. This is the first plant I've flowered in a SIP. She's drinking very well and doing great. The reservoir holds about a gallon of fertigation water, which gets used up in 1-2 days.
HI-BISCUS comparison grow, Triforce SIP on the left. I'm at the point where the reservoir needs to be filled every 1-2 days—fertigated down the tube. The big lesson in this first SIP grow was that fertigation should have been started at 2 weeks into the grow.
But to warden off bacteria might make sense, like an airstone in a DWC you don't really use that to provide oxygen to the roots, the roots can breathe from the water, you use that to keep bacteria from forming.
hmm yeah I'm currently operating with no holes, but previous grows as well but then I was using a lot of pebbles in between the water channel and the soil.. I even taped the four last time that connect to the reservoir as roots used to congregate there to try to get into the res. I had planned on making the holes if I switched to filling the SIP completely with soil but totally forgot.
