ReservoirDog
Well-Known Member
Sounds good, I do the same quite often. I have a couple "7 gallon" soft pots (in quotes because they take more soil than my '10 gallon' soft pots so, w.t.f.k.'s!) that have one of those velcro-fastened 'root' windows you can open, supposed to be for harvesting potatoes, or something with root veg, that slips into my 5 gallon pails exquisitely and because its taller actually increases my soil capacity. I think it's a good call and I would do it in every pot of I had the option. I do use softppots in my 27 gal tote SIPs, two 10 gal Geo Pots side by side, it keeps aeration up and competition between plants down.
I think it's an idea with merit. However, I can't recall how you were planning to answer the fertility question generally; are you fertigating (ie adding fertilizer mixed with water to the reservoir)? If so we need to consider that there is a threat of, over time, due to the passive nature of the system and conditions remaining the same for a long time, a toxicity/lockout taking place.
I use peat/perlite (promix or SS#4) which is prone to this issue due to its cation exchange rate however it comes very well buffered by the manufacturer and this appears to be critical. I also fertilize at a low rate, about 1.0 EC with excellent results, and I think @Buds Buddy is mixing much higher and using soils more similar to your own than mine - but the facts of the matter are that while we are not necessarily breaking new ground here, we do not have hard and fast, fact-backed answers with reams and reams of empirical data to back up every suggestion being made for SIPs currently.
I build in some fudge factors when operating in areas that have this 'lack of clarity'. In this case, thinking about the fact that this zone at the bottom of the planter is the same zone where this issue with too much nutrient is most likely to happen, or begin, and while the plants will surely experience a nice boost from the surprise Daddy and Mommy have buried at the bottom of the planter, I wouldn't want it in any way to lead to a negative development, long-term. I don't feel qualified to make a determination, I'm afraid, only to raise a note of caution.
Perhaps you could create vertical, "spikes" of spicy-dirt. When you fill the container put in place some vertically oriented object like a 500ml Coke bottle, or something, that you can then fill with the spicy-dirt, which the roots will find as they move outward, but by the time they get there the plant will be mature enough to make the most of what's there, yet you will have avoided causing a long-term issue.
However, I must stress that I have no idea whether a long-term issue is likely or even possible in this case. Lastly, my warnings here are applicable only if fertigating, that is, adding fertilizer mixed with water in the reservoir - a practice that is perfectly doable and will outperform other traditional grow methods but needs to be appreciated as having this potential. A mid-grow flush is an excellent prophylactic course of action, btw, even if I personally don't yet practise it.
Pleased to hear you were happy with it.
