Compost teas are a total gimmick imo. More often than not they throw your soil's balance out of whack and cause more problems than anything else. A properly made soil has no need for anything but water and the occasional top dress of organic amendments and compost.
Top dressing allows the plant and the microbes to be in control of things.. but when you make things into a tea you're making everything in the tea readily available to the plant, and if it's too much you're pretty much fucked. Say your soil has good enough NPK ratios to grow plants without any problems or deficiencies.. when you add compost tea to it you run the risk of actually burning your plants and toxicities.
Lets take bat guano for example, something like a 0-8-2 guano or something. When you top dress with guano and water it in, the microbes will slowly decompose the guano and the 0-8-2 NPK ratios will be steadily made available to the plant at the plant's own pace. When you make a tea out of that same guano though, you're essentially jump starting the composting process. Rather than the 0-8-2 guano being made available over an extended period of time at smaller amounts that the plant wants, you're making it immediately available and all at once.
If you find yourself needing to use teas of any sort, your soil likely wasn't made properly in the first place. Brewing teas with organic amendments like alfalfa meal, guanos, etc are akin to synthetic nutrients in the sense that both are made immediately available to the plant, so if you use too much you're in trouble.
HTH and if you have more questions feel free to shoot them my way and I'll answer them to the best of my ability.
