SIP thread -- (Sub-Irrigated Planter)

raggyb

Well-Known Member
Okay, I’ve just about completed my first grow in the 10-gallon SIPs. And I could use some other perspectives on an issue.

The SIP at issue is made of two 10-gallon Roughneck totes using a 5-inch net pot for a wicking channel. Photo below.

The issue is a dry corner. I tried top-watering slowly using yucca root powder in the water then re-filling the reservoir, but a week later that corner was dry again. I keep the soil covered with a plastic bag, but this container is not wicking as well as the other (different construction as well as different soil).

The soil in this SIP is Sohum amended with biochar, some dolomite lime, and extra mycos. The soil in the other SIP is FFOF with many more amendments, and it seems to be wicking well. Perhaps a bit too well, but that’s not a major issue at the moment. And I don’t remember which soil I used to pack the net pot in this particular SIP.

So, is it possible for a soil to be too loose, too fluffy, too aerated for effective use in a SIP?

Any input would be welcome, my plan was to re-amend the existing soil in place and re-run, but I think that dry corner would cause me issues with a heavier-feeding plant.

If this isn’t the place for this post, point me in the right direction forum-wise. This thread seems to be the experience-rich environment.

Edit : The corner in question is diagonallly opposite the fill tube.
I'm in the same boat making my own or you may be further along but if it were me I feel like you need 2 wicks for that size. So if you wanted to adjust that one maybe put a couple of 3 inch net pot wicks half way to the side of the one you got. I also have seen differences in water wicking between otherwise identical sips and the only explanation I could come up with was it was something to do with uneven packing of the soil. I follow 20/80% perlite/pete in the wick but don't know if that is best. It also sounds to me like maybe you could use more perlite if I understand.
 

meangreengrowinmachine

Well-Known Member
I always cover mine completely with panda film this time originally I used the og earthbox covers. Never had any issues. I'm moving to a soil bed just to have MORE soil. Hopefully it is just as easy as sips.
 

Hollatchaboy

Well-Known Member
That is a very good question...I really have no idea, I only mention it because even if you cover the top with plastic, there will still be a way for air to get into the soil, it won't be totally sealed off
Agreed. The roots can always get air from the bottom. Plus as the water level drops, I believe it can pull air in from the filler tube as well.
 

Tim Fox

Well-Known Member
Ya thats it,so no fear of lack of air? Id seal around the stems with rockwool.
Ok so cool I can seal it off then,thanks your pick helped.
I don't worry about air getting into the soil because of the air gap between the soil and the reservoir, the roots have an endless supply of oxygen in the air gap
 

Tim Fox

Well-Known Member
Agreed. The roots can always get air from the bottom. Plus as the water level drops, I believe it can pull air in from the filler tube as well.
That's my understanding that air goes inand out of the filler tube especially as water is used and re added , on mine the air gap is open on the front, on the sips in the beginning of this tread I believe people were drilling holes in the sides of storage tins at the height of the air gap , and also using airstones in the res if they wanted
 

meangreengrowinmachine

Well-Known Member
That's my understanding that air goes inand out of the filler tube especially as water is used and re added , on mine the air gap is open on the front, on the sips in the beginning of this tread I believe people were drilling holes in the sides of storage tins at the height of the air gap , and also using airstones in the res if they wanted
Also the earthbox is designed for air to go in the drain port and form an air pocket between the water and the soil. This way there will always be air in the root zone and water. In the initial pdf designs they have a water level view tube so you can see the water level but no drain. This meant no air gap except what could come through the filler tube. I belive a few of my home made sips suffered due to this small design flaw. Grantee the pdf is just a free source document that was made long ago so you cant ask too much of it.
 
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Bignutes

Well-Known Member
I have zero air gap, my wick only has holes in the bottom and it’s always submerged in reservoir. My plants grow like wildfire so ime an air gap isn’t needed. Air gap is just a byproduct of the design. Plants grown outside don’t have air gaps. Sips are about providing water as the plant requires, air gaps is bro science.
 
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GenericEnigma

Well-Known Member
I have zero air gap, my wick only has holes in the bottom and it’s always submerged in reservoir. My plants grow like wildfire so ime an air gap isn’t needed. Air gap is just a byproduct of the design. Plants grown outside don’t have air gaps. Sips are about providing water as the plant requires, air gaps is bro science.
In your system, is there an overfill hole, or do you carefully maintain water level? Air pressure must equalize through the soil if no hole? I can see how this would work with holes only in the bottom of a wick. Is your wick bigger in diameter than those we typically see here?

I never thought much about an air gap, but I definitely don't want the water level at the bottom of my soil (I'm afraid it would get oversaturated). I left a good gap in case of sag (I don't use a wick, so no spacers--just the gravel of a wicking bed in my reservoir). This must be what you mean by "byproduct."
 

Hollatchaboy

Well-Known Member
I have zero air gap, my wick only has holes in the bottom and it’s always submerged in reservoir. My plants grow like wildfire so ime an air gap isn’t needed. Air gap is just a byproduct of the design. Plants grown outside don’t have air gaps. Sips are about providing water as the plant requires, air gaps is bro science.
So in your opinion, roots don't need oxygen?
 

meangreengrowinmachine

Well-Known Member
I have zero air gap, my wick only has holes in the bottom and it’s always submerged in reservoir. My plants grow like wildfire so ime an air gap isn’t needed. Air gap is just a byproduct of the design. Plants grown outside don’t have air gaps. Sips are about providing water as the plant requires, air gaps is bro science.
Soil aeration is 100% a thing in nature... oxygen to the root zone is NOT bro science....
 
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