I am a big fan of compost tea, as I feel that it can really wake the soil up to it's potential by creating a microbial party. Some soils don't really need this, but it sure can work wonders in some cases. I also feel like after
enough rounds of applying tea you really don't need it much anymore. It is also very useful as a broad spectrum "medicine" for plants when something strange that you might not be able to figure out is going on. I like to foliar spray it for that purpose. Currently I only have
experience brewing up batches in a 5 gal bucket, but will be stepping up to a 55 gallon system here now that I have
land.
Here are my comments and tips on brewing good tea.......First off, you must make sure that you are pumping enough air through the water to be making a AACT(actively aerated compost tea) or else you risk breeding anaerobic bacteria that can actually do harm. I agree that a small pump with an airstone or two is enough for a 5gal, there is a formula for determining needed airflow if you want to know exactly. There is
alot more to the science of how the air moves through the water, that I am still learning more on....
I feel like the formula you are using is a bit on the heavy side in terms of ingredients. Good worm
poop goes a long way, I normally used a 1/2 cup which i believe is alot less then 1/2 lb. It is definitely benefical to use more then one source of compost for the brew, but really not much is needed. I was also using 1 tsp/gal of molasses and 1/4 tsp/gal of powdered kelp extract, or 5
tsp molasses and ~1 tsp kelp extract. Using too much sugar or kelp(another food source for the microbes) can negatively effect the tea.
A couple other things, for brew time 12-24 hrs seems to be the zone to shoot for according to the mad compost tea scientists(the folks who own microscopes, do research on formulas and run times and make their findings available). Apparently after 24 hrs the possibility of breeding nasties increases and i believe beneficials start dying off too. The one time i let a brew go 36 hours it didn't smell right and i dumped it. As for the water you use for brewing, make sure that it is chlorine and chloramine free. Chlorine can be bubbled off with the air stone in ~24hrs, or allowed to sit for at least 48 hrs with an open top to off gas before using. Chloramine however(which alot of municipalities are using now) won't off gas like chlorine and needs to be filtered out with a reverse osmosis filter(other stuff might work too). Well, spring, rain and you are good to go.
Thanks for posting on this, I do love compost tea and am always looking to learn more myself.......