What is the seed soil ratio needed for....?

You want to pre germinate WHY? Pre germinating grass seed is NOT a good idea. Follow the package directions and direct sow your seeds. Follow every instruction and recommendation on the package and you will have a lovely lawn. Skip a step or not water every day and you will waste your seed.

There is no need or advantage to pre germination.

Good luck

A severe Clay soil isn't an extremely stable substate for grasses and flora. there'll be continual soil chemistry and drainage problems with a clayish soil. If plausible, that's advisable to artwork to advance the clayish soil by skill of including SOIL AMENDMENTS jointly with greater suitable amazing-soils, composts, peat and humus. including some sand and gypsium additionally will help a severe clay content soil. Aeration on each year foundation will help quit compacting on a each year foundation. as quickly as the soil is greater, use seeds that are to your section based on the quantity of light you have on your backyard. community backyard save could have those.

it should say on the bag of seed