You don’t have to aerate the water if you’re using well water or another water source that doesn’t contain chlorine. [1] X Research source
Make sure the pump you use is capable of moving at least 5 gallons (19 L) of water. The pump system is necessary to aerate the compost tea as it brews. Stagnant tea will become anaerobic, and this won’t be good for your plants.
Be sure to use aged compost, because unfinished compost can contain harmful pathogens that you don’t want to spread onto your plants. [5] X Research source Mature compost will smell sweet and earthy rather than like alcohol or rotting food.
Use unsulfured molasses, because sulfur can kill the beneficial bacteria. [7] X Research source
The compost tea should always have an earthy smell. If that changes, throw out the batch and start again.
For the best results, apply compost tea to the soil two weeks before your plants start to bud. Compost tea is also a great soil addition for young plants and newly transplanted ones. [13] X Research source
The vegetable oil will help the tea stick to the leaves. Always use diluted tea on young or delicate plants. Don’t spray plants with foliar spray in the middle of the day, as the sun can burn the leaves.
