1 gallons dry out very quickly with coco, so expect to fertigate them 3 times per day minimum during flower (twice would probably work okay, but you'd have a definite wet/dry cycle, which isn't great in coco). I'd start feeding seedlings at .6, then up to .8 when they have a couple of nodes. Then it's just up to the individual plant, some sativas will show N tox symptoms at .8 ec...but most plants should be up to about 1 ec by the time you flower, and you might even need to go a little higher, like 1.2 during stretch. 1 to 1.2 is pretty typical through flower if you are fertigating several times per day, resist the temptation to go higher unless the plants need it. I'd shoot for perfect looking leaves-keep a close eye on them and adjust your feed, or add some additional epsom salts as needed. If you see any mag deficiency starting up during stretch, don't feed calmag, just give them a small amount of epsom salts- like .5 g per gallon. Oh, and just to be clear, water to 20% runoff each time you fertigate, it will prevent a lot of problems. Good luck to you! I'm a maxi series user but the salts are identical, hit me up if you need any help.