I mixed 1/2 teaspoon CalMag, FoxFarm Grow Big, and FoxFarm Tiger Boom into 1 gallon of distilled water and PH'd it to 6-6.5. The PPM level was 280PPM. I mixed it to feed some older pants, but not thinking, I used it on one 4 day old seedling and three 10 day old seedlings that are growing in FoxFarm Ocean Forrest. In your opinion and experience, do you think they should be alright, or should I flush it out now to be safe? .
Flush, the FFOF's premixed nutrients alone are enough for plants for a month. At one month, feed 1/4 dose of Grow Big(or your veg nute). Hold off on other nutes until late veg/early flower, just aren't necessary. It's not a bad thing to let them start to become slightly deficient so you know they actually need more food. Less is more.