For the last few weeks we’ve been taking out grow beds and cleaning like crazy.
We discussed our situation with a plant pathologist who wrote his dissertation on pythium. He told us that we would need to have everything that is possibly exposed to the pathogen be kept in contact with a disinfecting bleach solution for at least 30 minutes. This is because at some part of the life stage this fungus can survive contact with bleach up to 30 minutes. This is not simple as there are a lot of pieces that go into our deep water culture beds.
We strongly suspect that the pythium outbreak in our grow beds originated in the germination chamber. So step one was taking apart the germination chamber, scrubbing it down and then disinfecting it.
I did this myself as I want to make sure that it is thorough and I don’t know if I can convey how carefully I want it done to employees. It was a much bigger job than I expected. Once scrubbed down I covered it with a tarp and fogged the chamber (using a fogger) with hydrogen peroxide. I also sprayed any parts I was particularly concerned about with a strong bleach solution.
We then took out the plastic lining on all the grow beds and re-installed new plastic. Five are currently finished leaving 6 to go. It is slow because we like to harvest as much as we can from each one before moving on to the next.
After this we re-fill the beds and then add fertilizer.
I calculated the fertilizer by hand as we are having a lot of trouble with our machine (still) and I don’t want it to be wrong. (And if it is wrong, I want to know what was put in so that we can correct it.)
I put the fertilizer in two days ago just a few hours before I went on vacation (I’m visiting my fiance’s parents in British Colombia currently). The problem with adding this material by hand is that I mistakenly put the plants in before putting the fertilizer in. I could not mix the fertilizer into the water quickly enough so I am getting calls from the greenhouse to say that we have plants with burned tips. I’m quite sure that this is from having too high of an EC reading in the part of the bed where I added the fertilizer. We are mixing this water, but were too slow. I’m worried about the root damage that this might have caused. :/
This seems to be what growing is about. Solving a problem imperfectly and then dealing with the next problem. Each time you make a mistake you improve next time, but you kill a lot of plants in the process.