I do 3:1 70/30 but ya that is good. i always go from seedling pot to finishing pot. That way I only transplant 1 time the entire grow. If you do it this way just becareful with watering. I use 3 gallon grow bags. When I water the first couple of weeks I only give them about 1 qt. I alaways let them get pretty dry between waterings. That way the roots will grow out searching for moisture. When you plant your seedlings. Mix your medium and flush it and then let it drain for several hours. If you are using 16 oz solo cups use about 1 qt of water per to flush. Obviosly making sure you have drainage holes at the bottom. Once they sprout, I only give them about a shot glass of water every other day. Again making the roots stregthen. When you can see root tips coming out of the holes it is time to transplant. Again flush the medium with about 2-3 times the water as you have soil (in my 3 gal, I flush with 5 gal). I let it drain for 24 hours. Then transplant I don't start feeding until about 4 weeks after. That should give you a good 6-8 weeks before you need to start nutes. Feel free to PM if you have any questions.
