I use the same mother earth super tea grow/bloom. Really how often u use it depends on how often u need to water them. With mine outdoors, evaporation is so slow i only water roughtly each week so i feed them with each watering. Otherwise i start to see a nitrogen def. If ur indoors i imagine ul water them more often, so id say if its less than every week they need watering feed them every other watering. Really ull need to look out for N def and ul know from that.
When using synthetic (chemical) nutrients its important to go every other to reduce salts building up from what nutes the plant doesnt use. As far as im aware this doesnt apply to organics. ( Anyone please correct me if im wrong).
Just start low on the nutes n build up as u go. If ur soil already has a pre mix of nutrients in it ul not need to feed them untill u see N def as leaves turning pale green from the bottom up. I use biobizz allmix as a soil n this occurs after about 3-4 weeks. From ther i started on 1/4 strengh which was about 3.5ml per litre (am i right in sayin they recommend 7-15ml for use on its own).
Only today did i move up to 7.5 per litre and thats 3 months since they wer seedlings.
I hope this helps!