Howdy ; this is Halman9000 . After I Flush my pots I allow my humidity surrounding the seedlings to decrease to my winter room dry humidity at 10 to 20 percent on seedlings . My theory is that the roots of seedlings won't grow because the leaves will just absorb water from the air if the plant is surrounded by high humidity after flushing the medium . I still have my fan to move air through the plants to make them to respire . My experience is the roots only grow if the plant is forced to get water from flushed soil ( Being forced to get water from the soil and not the surrounding air is what I am trying to do ) . My theory developed after several attempt failures to get the seedlings to grow roots . I also , after a Flush , covering the wet soil will fine mulch in an attempt to increase wicking action to evaporate water from the very wet flushed soil , and add a layer of fine hay mulch to protect my seedling stems from high humidity . Once my seedlings grow I will check the root growth and if roots are growing and the medium has dried to a drier level , I will try raising my humidity surrounding my seedlings back to 40 to 80 percent Relative Humidity (RH ? )
Due to the low RH or humidity , dew point , ? , due to the low humidity and lack of much roots , the fine mulch on top , and the air having a low humidity ( all designed to make roots grow and to avoid mold on stem and leaves) , some of the seedlings start to look like they are shrinking from dryness and lack of nitroge , it still needs a little nutrients , so when I see the seedlings looking dried up I do a light nitrogen + water foliar spray . I could have tried to get nitrogen to the roots , but the fine hay mulch could use a small amount of nitrogen to begin to break down into finer pieces .
I am using humidity dome and have a humidity gauge inside the dome . After doing a light water + Urea ( nitrogen that works good for foliar spraying ; however it has more salt than nitrogen that releases somewhat slower ; which means I have to flush somewhat more ofter due to slightly faster salt build up ) . So I am trying to force the roots to grow and the more I use a foliar spray of nitrogen + water , the slower the roots will grow . However , if the seedlings run out of nitrogen and are starved for water they start to shrink and look less green , then at that point I am forced to due a light foliar nitrogen + water spray to put down a light covering of nitrogen + water onto the seedlings and the fine mulch so that I can close all of the vents on the humidity dome ( 7 inch tall dome ) , and I leave the dome on unless the seedlings and the mulch have time to fully absorb the water + nitrogen foliar feeding . I leave the dome on for about an hour and then slowly open the vents of the humidity dome , in small stages , until the seedlings look vigorous enough to allow more air to flow around the plants to restore respiration ,
The idea is to force the roots to grow , but there is a limit how quickly this can be done . The converse of the if you use a foliar spray of water + nitrogen too often and too much , then the roots won't grow and the plants will get infected with mold and bacteria and fungus and will eventually die .
So I have no choice at this point but use common sense to force the roots to grow , but feed it water and urea only enough to keep it vigorous enough to not die . I am probably making some mistakes due to lack of experience , but I should get better results this time around and with a lot of luck my plants won't die until they flower and run their normal life cycle .
The hard part is right after a flush and the medium is extremely wet ( I flush it alot until the water coming out of the pot is clear ) , At this point if I put it in the humidity dome and open the vents all the way and the fan is pointing at the dome , the humidity is still too high , in the the plant is not needing water from the roots and so the roots aren't growing . So far it seems that when the soil is really sopping wet , I have to either remove the dome or force high speed air through the humidity dome . I do both things , going back and forth . I bought a digital scale , and eventually I will be able to figure out when enough water has evaporated from the pots to go back to a normal humidity use and try to keep it at 40 percent humidity . My pots are starting to feel lighter , meaning the soil is getting less wet . I will start weighing the pots so I can relate weight to soil wetness . I can tell just by lifting up the pot how heavy it is , but I might as well weigh some of the pots with my scale so I can pretend I am being scientific .
Hallman9000