SIP Club - Getting Hydro/Coco Results In A Soil Based Medium

[RedskinnedRhino]

Greetings Growmies & SIPsters,

The Eagle Has Landed!

Please let me know if you have any suggested mods.

100% HDPE 5 gal SIP. (well it will be when I replace the PVC drain tube w/ HDPE 3/4" tube). 1-1/4" fill tube. 1 gal res.

The fill tube is friction-fit into the insert, so has an adjustable height. 4" drain tube is also friction-fit. Hole in the insert for the tube was cut with a jigsaw. I made the hole in the insert for the drain tube using a 3/4" hole drill (spade bit).

Volume of insert is 6.5 qt = 1.5 gal. So, volume for soil is 3.5 gal plus a bit.

Holes were made with a soldering iron.

Small 4" drain tube on left. The holes in the fill tube (right) were made with a drill—not good because of the burrs which are tedious to remove. Better to use a soldering iron.

Drain hole in the 5 gal bucket, center is 3.5" from bottom of bucket. I made this with a 1/2" hole drill (spade bit), which works well but it was too small for the 1/2" PCV, so I carefully enlarged it with my knife.

Soil lightly packed in around the insert. I did this a handful at a time, evenly, so that the insert is centered.

Thin layer of coarse perlite on top of the insert, to help block soil from entering.

The finished SIP. I ran out of soil... need make another batch! Also need to cut a piece of reflective bubble material, to wrap about the bucket to block light and heat.

I'd just spray paint it black, but that's my answer to alot of issues.
"A lil mud n a lil paint 'll make it somethin that it ain't! "

 

[cbdhemp808]

I'd just spray paint it black, but that's my answer to alot of issues.
"A lil mud n a lil paint 'll make it somethin that it ain't! "

Yeah, I chose this opaque bucket on purpose cuz it has measurement markings, and I'll maybe be able to see water level and root growth. I have lots of recycled reflective material, and the Hawaii sun is hot, so this is best... not black which would absorb heat. I will probably use just plain white HDPE buckets going forward.

 

[Azimuth]

Looking good @cbdhemp808 !

Next round put your fill tube closer to your overflow to make it easier to see when the rez is full. I'm right-handed so I put mine just to the right of the overflow.

 

[cbdhemp808]

I'm a little freaked out that the soil capacity is only 3.5 gal! Should I be freaked out?

I'm thinking about building another one tomorrow, and using the smaller 2-gal bucket for the insert, and see if I can get the insert volume down to 1 gal. I guess that means an air gap of about 1 inch. So then 4 gal soil capacity instead of 3.5. Does it really matter?

What's the approx height I'm shooting for, for flip?

 

[Azimuth]

A 1" air gap is perfect. I don't think more gets you anything but less soil capacity.

You're outdoors so no height restrictions to worry about, but you don't need that much of a harvest. I'm height restricted so I never let mine go much. On page 1 of this thread @Buds Buddy 's 1lb plant is shown to give you an idea if you take half his final height.

You probably don't need much veg time to hit your target.

 

[Gee64]

I'm a little freaked out that the soil capacity is only 3.5 gal! Should I be freaked out?

I'm thinking about building another one tomorrow, and using the smaller 2-gal bucket for the insert, and see if I can get the insert volume down to 1 gal. I guess that means an air gap of about 1 inch. So then 4 gal soil capacity instead of 3.5. Does it really matter?

What's the approx height I'm shooting for, for flip?

You could always cut the bottom off a 2nd bucket, drop it in, and extend the fill tube. That would add a couple of gallons of space.

 

[cbdhemp808]

You could always cut the bottom off a 2nd bucket, drop it in, and extend the fill tube. That would add a couple of gallons of space.

Thanks, good idea, but... I'm shooting for an 8 oz. yield, so it seems I can get there without additional soil space. I'll build another SIP and try to gain 1/2 gal by using a smaller insert. (The one I just built will probably be ideal for my amazing little indica CBD #18 pheno of Cherry Blossom. Oh man, I can't wait to see what she can do in a SIP!)

Here's @Buds Buddy 's plant in a 5G SIP from 2022... I think he got 1 lb.

Buds, was this 4 gal soil space? Clone or seed? And how long in veg?

EDIT: Buds said on my thread...

I only grow Indica. I believe that was a "Cherry On Top" plant if I remember right. Grown in FFOF with Mega Crop, Monosilicic Acid & Nitrogen using @InTheShed Feeding Calculations. During Bloom I was filling the res twice per day during the last couple of weeks because they drink a hell of a lot.

 

[cbdhemp808]

Some good info from @Buds Buddy , from my thread, worth repeating...

Personally, if I was only looking to get 8 oz. I'd start my plant in a 1 gal pot. Veg about 4 weeks & up pot to a 5 gallon SIP.
Give it about 3 days to recover from the up pot & flip to 12/12. No need to veg any longer to get 8 oz. using a SIP. Now that I grow in SIP's I love to grow big ass plants.

I'm growing clones of clones, so it's a different story than seed, yeah? I'd be going for plant size in veg.

 

[TequilaSIPr]

Hello all! Day 65 just added my 1200w into the tent the smell on my fingers when i supercrop her is delicious tag along if you will!

 

[cbdhemp808]

My question now is...

Is vertical air space better than horizontal air space?

Here's a new design for a SIP insert. Let me know what you think!

Today I found a 1 gal HDPE bucket that I had lying around, that used to contain coconut oil. I thought, why not use this in the SIP? After all, the volume is exactly 1 gal already... no cutting necessary.

1 gal HDPE bucket, upside down. Showing height (7-3/8"), comparison to height of GroBucket insert (4.8"), and position of GroBucket drain hole (3-1/2").

I compared this stock 1 gal bucket to the 2 gal ACE bucket that I was planning on cutting down to 1 gal. The stock 1 gal bucket has more vertical space, while the modified ACE bucket would have more horizontal space.

Which is better in the bottom of the SIP? (Note: I calculated the volume of the GroBucket insert to also be 1 gal.)

The stock 1 gal bucket is 7-3/8" tall, while the modified 2-gal bucket is 4-1/4" tall. (The modified 2-gal bucket is actually similar in height to the GroBucket insert pictured below, which I calculated to be 4.8".)

GroBucket insert, showing height/width ratio.

GroBucket insert showing (left) air vents on the top, but no air vents on the side, and (right) flange at the bottom.

photos: Peter Stanley video

The benefit of the 7-3/8" height, and narrow base, is that a bigger wicking area is created. (In terms of the doughnut analogy, a taller, fatter doughnut with a smaller hole.) The 1 gal bucket is about 2-1/2" taller than the GroBucket insert, and when invert in the bottom of the SIP bucket, the base is 3/4" smaller.

So I have a choice now for the insert between using: (A) modified ACE 2-gal bucket, or (B) stock 1 gal bucket. Both have 1 gal volume, so they leave 4 gal of soil space in the SIP.

Option A is similar in height/width as a GroBucket insert, providing similar air venting at the top of the insert, and approx. 1" air space. Option B is 3" taller than Option A, providing about 1-1/2" less diameter for (horizontal) air venting space at the top, and 3" more potential vertical air space.

Here are the beneficial features of Option B, the stock 1 gal bucket...

1. No need to cut a bucket and create waste
2. 1 gal HDPE buckets are cheaper than 2 gal ones
3. The wick area will be substantially larger, and will extend an additional 3 inches up into the bucket
4. The wick area being larger allows for more root mass in the reservoir
5. The reservoir can be bigger, because the restriction of 3.5" from the base of the bucket is lifted (because the top of the insert is 3" higher)
6. Provides an adjustable trade-off between air space and reservoir size
7. Lots of vent holes can be added to the sides of the insert above the reservoir in the air space (4" vertical max. to work with)
8. There is an option to have no air vent holes (or a lot less) at the top of the insert, since there are now vents on the side, which would then eliminate/reduce soil from entering the insert from the top, and eliminate the need for a perlite layer
9. Shorter filling tube
10. Lastly, there's the option to modify the 1 gal bucket, reduce its height, and gain more soil space. This would be at the expense of losing some aeration—probably not worth it.

From what I can tell, this design will provide: better wicking, a bigger reservoir, better aeration of the roots, more space for roots in the reservoir, and less soil infiltration into the insert, with no sacrifice of space for soil.

What I would do is move the reservoir level up 3/4" to the 4-1/4" mark (pictured below) , leaving around 3" of insert side wall above the level of the reservoir, and this is where the air vent holes would be... lots of small holes (vertical air space). I would put no holes on the top of the insert (or maybe just a small number). This is a gain of a little over 1/2 gal of reservoir capacity, which I think is a good starting point to test. I sense that too big of a reservoir may lead to problems. (I just realized that there could be two drain holes—one for a small res and one for a large res. The plant would be started w/ the small res, and graduated to the large res at its peak growth. A simple cork would be used to block the hole not in use.)

5 gal SIP bucket showing position of drain hole—standard 3.5", and increased res size 4.25". Water level in the res is not affected by the size or shape of the insert, because water flows inside and around the insert, seeking its own level.

It kind of blows my mind that this 1 gal insert is taking up half the height of the 5 gal bucket, while the soil volume is still 4 gallons...

What do you think, folks? Is this a next-level DIY super SIP, or am I missing something? Does this provide more oxygen to the roots, or less oxygen to the roots?

EDIT: I'm thinking now to use more perlite in my soil mix, to encourage aeration throughout. Also, more worm castings for beneficial microbes.

 

[Azimuth]

And there he goes, falling down the rabbit hole. Welcome to SIP Club! Growing with these things is addictive and a bit of a disease for which there is no known cure.

I like your thinking and I'll weigh in with my perspective but encourage others to do so as well.

I don't think a taller reservoir bucket has advantages over a shorter one. I too thought more soil in the water would allow for more wicking so I built my SIPs accordingly but I found that in my shorter 2G buckets that the soil stayed too wet to grow high brix plants which has become my primary goal. The plants looked good and grew well, but I couldn't get the brix levels up. I'd imagine that would be much less of an issue with taller buckets since the perched water table will be at a much lower level percentage of bucket height wise than for mine and I think that was a large part of my issues.

StoneOtter grows in Earthboxes and his plants do brix at higher levels. I have other issues with my soil mix that probably exacerbate my issues, but all that to say that a smaller amount of soil in the reservoir works every bit as good and maybe better than more. The standard 5 gallon bucket-in-bucket design uses only a 4" net pot as its soil-to-water bridge and those work great. I've since scaled my connector pots down proportionally.

I'd say try the easier one to build and see how it works for you. Any time you deviate from the tried and true builds you're a bit out there on your own, but often that's half the fun!

 

[cbdhemp808]

And there he goes, falling down the rabbit hole. Welcome to SIP Club! Growing with these things is addictive and a bit of a disease for which there is no known cure.

I like your thinking and I'll weigh in with my perspective but encourage others to do so as well.

I don't think a taller reservoir bucket has advantages over a shorter one. I too thought more soil in the water would allow for more wicking so I built my SIPs accordingly but I found that in my shorter 2G buckets that the soil stayed too wet to grow high brix plants which has become my primary goal. The plants looked good and grew well, but I couldn't get the brix levels up. I'd imagine that would be much less of an issue with taller buckets since the perched water table will be at a much lower level percentage of bucket height wise than for mine and I think that was a large part of my issues.

StoneOtter grows in Earthboxes and his plants do brix at higher levels. I have other issues with my soil mix that probably exacerbate my issues, but all that to say that a smaller amount of soil in the reservoir works every bit as good and maybe better than more. The standard 5 gallon bucket-in-bucket design uses only a 4" net pot as its soil-to-water bridge and those work great. I've since scaled my connector pots down proportionally.

I'd say try the easier one to build and see how it works for you. Any time you deviate from the tried and true builds you're a bit out there on your own, but often that's half the fun!

Yes, I am definitely down the rabbit hole and wondering whether to take the pill that makes me larger or smaller, and having delusions that SIPs could possibly even save the world. (Maybe it was that puff I took on the caterpillar's hookah.)

I think I'm gonna build this one with the 1 gal. bucket insert. To me it seems very intuitive that the larger the "doughnut" the more roots will be able to enjoy the reservoir, and the more that are in there, the faster the water will get sucked up. I have no idea if it would mean more wicking upward, but don't see why not. As for oxygen, it seems having lots of holes on the side of the insert would mean more access to oxygen for the roots that are accessing the res. As the roots drink, and the water level falls, it seems that would pull oxygen into the root mass. The more roots, the faster the action. Also, more space in the wick area would mean more space around the roots, instead of them being packed together, which would probably help with oxygen as well.

I can sort of see some similarities between the 1 gal. insert w/ air holes on the sides and the bucket-in-bucket with the net pot. The 1 gal. insert is kind of like the net pot "turned inside out". The big difference with the net pot style is that there's a large water-to-air interface (surface area). I can see that would provide easy access to air for the roots, even though the roots are reaching the res by going through holes in the upper bucket bottom. The big difference for the insert style is the opposite—smaller water-to-air interface—and the roots don't have direct access to that area. The roots are free to easily access the reservoir, but there's no open water-to-air interface there. Instead, the air comes from inside the insert. Even so, a GroBucket style system produces excellent results.

It would be great to do a side-by-side comparison, with identical clones, of the 1 gal. insert, and the one I just built with the insert that's more similar to the GroBucket insert. I would choose my strongest pheno, Humboldt Dream. To do that, I'll need another generation of clones, since the current ones are getting too big in 1 gal. pots, and I don't want to use root bound clones. I'll also need to use the same batch of soil, so I need to make a new batch. I'm gonna add more perlite and worm castings than usual.

EDIT: For the side-by-side comparison I'd actually use the stock 1 gal. bucket vs. the modified ACE 2 gal. bucket. So, I would re-build the SIP I just built, and use the modified ACE (1 gal). I need to remove the soil anyway. The modified ACE is actually very similar in dimensions to the GroBucket insert.

 

[cbdhemp808]

As for oxygen, it seems having lots of holes on the side of the insert would mean more access to oxygen for the roots that are accessing the res. As the roots drink, and the water level falls, it seems that would pull oxygen into the root mass. The more roots, the faster the action. Also, more space in the wick area would mean more space around the roots, instead of them being packed together, which would probably help with oxygen as well.

Now I'm wondering how the roots actually absorb oxygen. It seems roots get oxygen from both dissolved oxygen in the water, and from air that permeates the soil. Roots down in a full reservoir will be limited to getting their oxygen from dissolved oxygen in the water. Roots sitting in water that is depleted of oxygen will starve for oxygen.

Here's a diagram to refer to, for comparing SIPs, and for thinking about: how the roots grow in the pot, the dynamics of how air is distributed in the system, and how the roots absorb oxygen.

S = soil, A = air, W = water, R = roots in soil in the reservoir.

Note that "R" is the most direct way for the roots to enter the reservoir. All three styles above also allow roots to enter the water from the S/A interface, through holes [EDIT: Apparently not many roots do this]. In the case of the grow bucket styles, the holes are "air vents". For the bucket-in-bucket style, the holes are intentionally plentiful and larger, to accommodate root intrusion.

 

[Azimuth]

Nice diagram.

I've found that only a few adventurous roots will transit the air section to find the water. Most follow the easy path through the connector sections.

 

[cbdhemp808]

Nice diagram.

I've found that only a few adventurous roots will transit the air section to find the water. Most follow the easy path through the connector sections.

Interesting & thanks for that. I have corrected the above. So the holes and slots are there strictly for air passage into the soil. Have you or anyone experimented with larger net pots?

One reason I like the design of the "tall insert" is that many holes can be placed on the side of the insert; not just above the high water line of the reservoir, but all the way down the sides. Because, as the reservoir level goes down, more air will be provided in the "R" root areas (see chart above). I think I'd go all out and include the holes at the top of the insert as well, and put a layer of perlite above that, to maximize air passage into the soil. I'm seeing this as one of the main goals of SIP design.

It seems roots get oxygen from both dissolved oxygen in the water, and from air that permeates the soil.

I think in the 3 designs in the chart, oxygen is being made available mainly through the soil. I guess there would be a minimal amount being dissolved in the water, simply from the air being in contact with the surface of the water. This is why they use air stones, to inject oxygen into the water. Turbulence also increases oxygenation.

 

[BeyondClouds]

Interesting & thanks for that. I have corrected the above. So the holes and slots are there strictly for air passage into the soil. Have you or anyone experimented with larger net pots?

One reason I like the design of the "tall insert" is that many holes can be placed on the side of the insert; not just above the high water line of the reservoir, but all the way down the sides. Because, as the reservoir level goes down, more air will be provided in the "R" root areas (see chart above). I think I'd go all out and include the holes at the top of the insert as well, and put a layer of perlite above that, to maximize air passage into the soil. I'm seeing this as one of the main goals of SIP design.


I think in the 3 designs in the chart, oxygen is being made available mainly through the soil. I guess there would be a minimal amount being dissolved in the water, simply from the air being in contact with the surface of the water. This is why they use air stones, to inject oxygen into the water. Turbulence also increases oxygenation.

Oi @cbdhemp808. My setup is pretty much a longer foot with alot of air-room…the reservoir maxes out at 4l, I haven‘t thrown more than 3l at it….i have put holes in the base of the container as well as low on the sides….as far I‘m happy …but I’ll be honest…first SIP / 2-grow-newb / a lil‘ cheating on the Club cause once-a-week topdressing

 

[BeyondClouds]

Oh….and of course I’m voting for the the footer/net pot option ….thinking that this setup will allow the soil/roots „collect“ more air/oxygen because the lowest part of the container won‘t be as saturated as long as in the dome version.

 

[cbdhemp808]

My setup is pretty much a longer foot with alot of air-room…the reservoir maxes out at 4l, I haven‘t thrown more than 3l at it….i have put holes in the base of the container as well as low on the sides….as far I‘m happy …but I’ll be honest…first SIP / 2-grow-newb / a lil‘ cheating on the Club cause once-a-week topdressing

Oh….and of course I’m voting for the the footer/net pot option ….thinking that this setup will allow the soil/roots „collect“ more air/oxygen because the lowest part of the container won‘t be as saturated as long as in the dome version.

Hey Clouds, do you mean you are using bucket-in-bucket type, with a lot of holes drilled in the bottom of the top bucket? And then what you call the "foot" is a large net pot (wider horizontally), or a pot serving as a net pot with a lot of holes in the base and along the sides?

Good to hear these SIP terms like "foot" and "dome", so I know what folks are talking about here.

RE: "allow the soil/roots „collect“ more air/oxygen because the lowest part of the container won‘t be as saturated as long as in the dome version" ...

I don't follow you there, because the action is basically the same, from what I can tell... see the "R" zone in the chart. That zone is always the lowest part of the container. I think what matters is the soil surface area in contact with the reservoir water (size of "R"). It seems to me that the bigger "R" is, the more roots will inhabit that zone, and the faster the water will be consumed by the roots (depends on the age of the plant). Well, in the two dome versions in the chart here, I'm actually not sure which would be faster at lowering the res level, because a small "R" would mean lots of roots competing for that zone. Again, depends on the size/age of the plant and how big the root mass has become. For example, initially a young plant will be slow at draining the res with the "tall insert" design, because "R" is bigger.

 

[Azimuth]

Have you or anyone experimented with larger net pots?

In a sort. I made my own footer cup from a bread crumb container, 4" across, in my original design. I thought that even more soil/water contact would be better so I changed to the mirror image version with a dome for the reservoir void surrounded by soil.

I've since gone back to the original wicking footer design but with an even smaller connector cup to match the relative scale of the 5G bucket designs. Too early to tell the results from it though.

I think I'd go all out and include the holes at the top of the insert as well, and put a layer of perlite above that, to maximize air passage into the soil. I'm seeing this as one of the main goals of SIP design.

I've never seen a need for that perlite layer though it won't hurt anything. I have dual fill tubes on opposite sides of the container with the thought that that would increase the chances for air flow in the reservoir.

 

[can1mar]

Hi all, a new(bie) member here. I was thinking of making my second grow with a sip but have couple of questions:

I was thinking of going with this setup, indoor, 42l container (~10g)

with Mona Plant Watering Tank 10Ltr insert

which translates rougly in 1/4th of available container volume.

Now, the insert doesn't look like it has a overflow prevention, I might add one or be lazy and judge the water level by the floater. With this design there is not an air chamber, do I need one though?


Also, with the whole SIP system it's not very clear what feeding strategy to use? DWC like with tds metering, or the same as organic one?


My market is UK if that helps. Cheers.