As an update to the above: one thing that I figured out is the water temp was changing too quickly for the plants. Recently it could be 80-90+(?) during the day from absorbing sun for 6+ hours, but then drop to 40 at night and the plant would be all droopy in the morning. Lost 2 sections of my bell pepper plant this way :(.
I'm pretty sure in the summer the opposite was happening - normal temp at night, but then way too hot during the day, then recover again at night. I guess thats another good argument for SIPs.
Anyway, with frost potentially coming in the next 2+ weeks and the above temp issues, I brought the plants inside for the winter. I made a light by sticking LEDs to the underside of a shelf and powered them with a power supply from a junk box (5A power supply, 2A worth of lights - the 3.5A power supply couldn't maintain 2A output without overheating).
Next step is to insulate with reflective insulation to hopefully trap some of the heat from the lights. This lives in the basement which is unheated and usually drops into the mid 50s in the winter. I'd like to keep it closer to 75 by the plants because I read that will help the pepper plants produce more.
Haven't figured out what I am going to do about a fan/if it is really necessary yet.
Garden prep time is rapidly approaching. This year I want to give SIPs a try (outside) in some simple food safe buckets. I have some questions:
- How far below the top of the soil should the top of the waterline be?
- How much air gap should there be?
- If I am doing this is buckets, how far apart do my plants need to be? The same amount as if they were in the ground, or can I compress them closer together?
- For smaller herbs (Basil) can I grow 2x plants in one bucket?
- The pcv fill-tube you often see... is that necessary? Does it just speed up filling, or accomplish something else? Water should filter right through the soil, right?
Goals this year are:
Tomatoes, tomatoes, tomatoes.
Jalapenos and a variety of other peppers if possible.
Basil, Oregano, and maybe a few other herbs.
Lettuce and spinach.
Final question
5 gal bucket of dirt and a decent light. Simple setup and my "lettuce" is doing well. 
Bump any thoughts on this?
ProDarwin said:
Garden prep time is rapidly approaching. This year I want to give SIPs a try (outside) in some simple food safe buckets. I have some questions:
- How far below the top of the soil should the top of the waterline be?
- How much air gap should there be?
- If I am doing this is buckets, how far apart do my plants need to be? The same amount as if they were in the ground, or can I compress them closer together?
- For smaller herbs (Basil) can I grow 2x plants in one bucket?
- The pcv fill-tube you often see... is that necessary? Does it just speed up filling, or accomplish something else? Water should filter right through the soil, right?
You should try to leave a 1 inch air gap between the water and the lid. This is necessary to keep the flow of water going.
On that note, you should really try to prevent water from getting to the soil from above after you get them setup. That will slow down, if not entirely stop, the capillary action of the SIP, which is the main purpose behind using them. You're creating an isolated, self watering growing medium that you alone control.
Smaller stuff, like basil or lettuce, can definitely be done in the same bucket.
Because larger plants will have isolated root systems, you can put the buckets side by side, or even make a big trough system. Example, say you're using 27 gallon totes, you can put 2 five gallon smart pots, or 3 two gallon, on the lid as long as you give each one their own capillary tube. You should probably exercise some training to keep the plants from growing together as they grow up, that does stress plants out, but as long as you stay up on it, you can put buckets side by side.
Also, I wouldn't advise this got hot peppers. It's my understanding and experience that hot peppers prefer their soil to be dryer than this method allows.
I don't understand how water in the top soil stops the capillary action. Yes, while the top soil is moist, it wont pull water from below, but... its got water in it, so that's not necessary. As it dries out it will begin to pull water up from the reservoir, right? This is what happens when it rains.
I'm trying to avoid having a sprinkler setup, and I feel like rain only is not going to workout well for hot peppers. Maybe. Can I just use a smaller reservoir w/ a larger air gap?
Think of a sponge in the sink. If you stick a dry sponge in the sink, it will suck up whatever leftover water there is. But, if you drop a wet sponge in the sink, it's not going to do anything.
I don't know what your rain situation is down in the Carolinas, probably better than my 300 days of rain a year here in PA at least.
The other issue is that rain going down through the top is going to put more of the nutrients and actual dirt from the pots into the reservoir. Now if things are absolutely perfect that should seemingly not be a problem. In an indoor setup. But you would have nutrients, bacteria, microchorrizai(I butchered that spelling), or salts depending on your nutrient choices, in the soil that will go down into the reservoir, creating algae and basically swamp water. Unless you want to be cleaning the reservoir every week or so, this build up will not be beneficial to the plants.
For hot peppers, I just leave them in regular pots, and water then maybe once a month once they've started. Jalapenos maybe not so picky, but if your trying to grow actual hot peppers, they need a draught period to really push growth and capsaicin. Think of them more as succulents.
I should update this:
Last year I did the sub irrigated planters in 5 gallon buckets. They were great except:
1) Tomatoes drink water too fast. Not enough reservoir. I had to refill every couple days.
2) They look ugly.
The peppers in the SIPs did WAY better than those just in the ground, even though I watered them both. So I don't see a reason not to keep them in SIPs again this year. I only did Cayenne and Jalapeno though last year. This year I'm doing bell peppers, habanero, poblano, & serrano also. This pic was from july. I had to cut the tomatoes back once they grew over the top of the trellis and let them grow up again. They almost reached the top a 2nd time.
This year I am fixing the two big issues above with a couple of bigass feed tank planters. They will look pretty clean and have a much larger reservoir. They will also be a little easier to deal with re: fertilizing, filling, etc as numerous plants are covered from one spot. Planter 1 of 2 pictured below:
One question re: fertilizing... what is the best way to fertilize stuff in SIPs? From the bottom, or mix it and apply to soil from the top?
In reply to ProDarwin :
Mixing into the soil. Compost or powdered nutrients, something slow release. Nutrients sitting in still water for a long time can do all sorts of nasty stuff to plants and the reservoir.
Glad to see the SIPs worked out for you, especially with those peppers.
