Edit: for clarity and some further instructions.
Add pre-dampened/moistened soil with 40% perlite to bucket. (if dust-fart dry some mixes can become hydrophobic and absorb moisture unevenly). Do not create layers of perlite or other additives. No manures other than worm castings, unless amounts are less than 1 cup in total. Limit compost to 1 cup/gallon. With manures you are likely to create a nitrogen soup in the reservoir attractive to death-dealing microbes. Compost holds a great deal of moisture, but SIPs self-water so this retentive quality is not needed and we are more concerned with not holding too much moisture. That is why 40% perlite is critical. Strictly moderate your compost. Hard, I know.
24 hours
before transplanting small seedling or planting germ'd seed
FIll reservoir to allow the grow matrix (soil, or peat/perlite pre-mixes like ProMix, Sunshine Mix #4) to absorb water. After 24 hr even if top 1/2 inch is dry you will see moisture below that and that is all you need or want. The idea is for there to be only 1/2 full reservoir or less remaining after 24hrs of absorption.
After 24 hours confirm system has absorbed half or more than half of the approx one gallon of water the reservoir holds. If reservoir is over half full after 24 hrs simply wait for evaporation to take place over a few day before planting. You do not want to plant with reservoir over half full after initial absorption.
After minimum 24hours absorption and confirmation that reservoir is half to 1/3 full then proceeded with planting. I, and Octopot whose manual I am paraphrasing, do not recommend starting seedlings or seeds in a system that has reservoir over half full.
Why? Because advantage of the system is that plants can revert to their natural root building 'scheme' in a container with a moisture gradient. Normal container growing cannot recreate a moisture gradient, thus its inferiority compared to proper SIP growing. But it dependent on grower to appreciate this requirement and understand some basics. Such as: When reservoir is full a gradient still exists, however, the difference in moisture level between top and bottom is less so than when the reservoir is less full. Germ'd seeds and seedlings require the extra "hint" that best conditions lie below, deep below, and will expedite a taproot to go deep when the gradient is obvious. Maintain these levels for two weeks.
The above information should answer your questions about top watering frequency because there's nothing you can do that destroys the moisture gradient and the plant's ability to perceive its existence
more than top watering. Common sense. You have a "self watering' pot with a reservoir. Never water your plant any other way unless it is fully mature and even then you need a good excuse, like the need for a certain input, s special fertilizer or some such. My SIPs are totally dry in first 1-3 cm, this is normal and good. Mulch if it scares you but it won't hurt plant and will reduce fungi/mold/bug threats. It's not about the roots "hitting the reservoir" like DWC, they are getting oxygen and food/water in the soil matrix if its well aerated (40% perlite) and you have overflow hole drilled. It's about 'hydrotropism" and the huge efficiencies that delivers over the plants in traditional container gardening because SIP plant is in a comparatively steady-state, and not bouncing back and forth between the compromised states of soaking wet, and almost dry. Time-lapse comparisons confirm this. SIPs grow steadily, constantly. Traditional containers grow right after watering, then pause through the dry-out we must impose in that system to wait for water to come again.
Yes, when you transplants a seedling, or a germinated or un germinated seed you need to water it in with less than a pint/liter of water to close any air gaps immediately around the plant/seed, but that is all. If you top water again, esp. in the next 2-3 weeks, you will significantly slow development. You do not need to top water, ever nor should you unless you are applying a special input that you'd rather not have in the reservoir.
Also, if you are creating a seedling for transplant, plant it before 5th node, after 2nd node is fine. Also, even before its in a SIP, bottom water your seedling while it's developing to kickstart its "moisture gradient" muscle memory.
Lastly, transplants of mature plants
from a container over 3 gallons are not recommended. No advantage will accrue as the plant is unlikely to any longer be able to access its genetic memory of moisture gradient-steered hydrotropism at such an advanced state of root development. It seems pot size is key here, however, so plants originally in pots smaller than 3 gal may still be successfully transplanted and will, after an adaption period, show intense growth. This is by no means preferable, however, to planting small seedlings or germed seeds as the adaption period of any mature plant can become painfully extended or even unending in rare cases.
Otherwise intelligent growers will argue some points above about planting germ'd seeds or seedlings, but, they're usually not experienced SIP growers and, again, this information I'm giving you is from a successful SIP-only company, developed by horticulture/agriculture PHds, following proven scientific principals that have practically proven themselves during product development and later customer use to work and be superior to other approaches. Octopot, in my humble estimation, is probably the best off-the-shelf grow system in the world, bar none, given what you must put in compared to what you get out. However, you can rest assured that these are SIP-specific principles, not merely Octopot-only rules. Do yourself a huge favour and go
here to download their user guide. A great majority of the issues and questions you might have are addressed. Reference it constantly, it will not steer you wrong.
I personally plant 2-3 node seedlings into SIP as my preference but I am sure to bottom water these plants, very sparingly, from the first days after germination so they've already experienced a bottom-heavy moisture gradient before going in the SIP. If you grow seedling in normal container that's been top watered your seedling will be at a distinct disadvantage when transplanted, in particular the longer you wait.
Best of luck to you, feel free to PM me for discussion if you wish.
