Check this thread out, read through it and it will answer all your questions. https://www.icmag.com/ic/showthread.php?t=110620
Microbeorganics.com is another fantastic site for learning about ACT's. It also has what to put in teas, at what quantities. It has your exact ingredients, except the kelp is not water soluble, it is feed form. You can do a brew with just EWC and molasses.
To answer your question:
for every 5 gal of water:
1.9 cups EWC
.4 cups unsulfered mollasses
.15 cups soluble kelp
I would brew this for 36 hours at 70 degrees F.
(cut and paste from Microbeorganics.com)
"Length of Brew;
This will provide a CT with a microbial content of, bacteria/archaea and fungal hyphae (if present in compost) when brewed for 18 to 24 hours. When using our fungal inhabited vermicompost, the optimum time seems to be 18 hours for a bacteria/archaea and fungal brew. If brewed for 30 to 36 hours (and up to 42 to 48 hours if you have a microscope) there will be flagellates and amoebae (& some ciliates) as well, providing a functioning microbial consortia which is better for nutrient cycling in the soil/root interface. Because of the variations in brewing compost tea, it is better to examine the microbial content with a microscope and decide at what period of the brew you should apply it but if you do not have a microscope then use the CT between the time periods mentioned above for the desired effects. "
