The size and health of the plants will never dictate your question. You have to consider the nutrients accordingly to the stage of growth they are in. Now your pistils are out which means the plant wants to produce her fruits so she will need more Phosphorous and Potassium and less Nitrogen. Only thing you can control now is the flower development. Super Lemon is a fantastic strain btw, you'll love it if you give it a proper cure you'll taste and smell the limonene terpenes ;)