Flood tables for germinating seeds -
I want to build a flood table to germinate seeds with harvested rainwater and using a growing mix of 20% vermiculite 70% coir and 10% worm castings. The water is to be cycled through a cistern with aeration to a ebb/flood table that will fill 1" and drain into sump with pump .
What are the chances of getting a seedling killing disease and it contaminating every seedling on the table.
If you have two cents, would greatly appreciate it.
Vermi poop is considered clean so no worries about that but I'd suggest something that drains better than coir if no under hot conditions or short duration between cycles. Maybe 100% sand might work better for starting seeds?
As for contamination; I'm afraid the grower would be the most likely culprit. There are many possibilities of contamination from dirty hands to airborne stuff to seeds themselves. Mold is usually my main concern. So develop hygiene habbits suggested in hydroponic sites and you should be fine. Proper environments discourage problems...however when talking about gardening, its kind of up the the kindness of nature and fate that has any guarantee of good results.
Good air circulation and light often help against many problems with seedlings, and getting your seeds from a good source, and keeping the rodents from digging up your seedling mix looking for worms. (I start my seeds outdoors often in peat pellets and the squirrels have a strange obsession for I guess sucking the moisture from the peat or something and other critters like to dig in search of tasty worms.)
Keep water very well aerated and find the right balance of moisture to media and you will probably be in good shape, just gotta design the seed starting mix right. I've actually found that instead of flooding seed trays I do better setting the already properly moist seed tray on capillary matting that is hanging into a gutter of AP water and only wicks up the appropriate amount of moisture.
I understand that potassium deficiency tends to make plants prone to powdery mildew and some types of plants are really prone to being attached no matter what.
I've heard of many methods to combat powdery mildew but many of them may actually be more appropriate to downey mildew instead.
I would probably recommend a foliar spray of seaweed extract or potassium bicarbonate.
I have posted pics on my site of 50% compost and 50% worm castings mix in plastic seedling containers with seedlings sprouting. This was started when I started cycling a brand new system. Three weeks later the system is in balance, I have added fish and I really need to get the seedlings outta there as they have gotten huge!!! (I'll post pics). My only disease problem to date is powdery mildew which I also have in my soil based garden and is (unfortunately) endemic to the area. Any one have an organic cure for that??