What do you do if you have already started your seeds and maybe you are seeing a few gnats or some fungus, or maybe you have lost a few seedlings to damping off? There are a few methods of rescue to help you get things under control without having to throw everything out and start over.
The first and most important thing to do is slow down on your watering cycle, over-watering is the most common problem when starting new seeds and it can cause an entire host of other issues. Fungus needs moisture to bloom, so if you allow the soil to dry out a bit, this will cut down the fungal infection tremendously. If there is a visible accumulation of fungi on the soil surface, scrape it off carefully. The use of a small fan on the lowest setting will help to speed the drying process.
Next cover your soil with an even layer of fine sand until you see no open areas of soil. This will stop any gnat larvae that may hatch from within the soil from coming to the surface to feed on remaining fungi. They will then starve, suffocate and die off. For any remaining adult gnats, mix six to eight ounces of apple cider vinegar with a few drops of dish soap and sit several small containers of this mixture among your seedlings in your growing area. The gnats will be drawn to the smell of the apple cider vinegar, and the soap will cut the surface tension of the liquid allowing the gnats to fall in and drown.
To treat your seedlings for any remaining fungal spores, gently mist your plants with a very dilute neem oil solution (one tbsp neem oil, one tsp soap, one gallon of water). You may also use regular strength chamomile tea as a mist over your seedlings, both methods are safe and organic antifungal choices.