Advice to save this plant

To me, she looks thirsty and starving. Make sure to give enough water that it flows from the bottom of the pot, otherwise there is no way to tell if the substrate is thoroughly moistened from top to bottom. This may take as much as 2-3 litres. The most effective way of addressing what could be over dry soil is to give say 500ml of water every half an hour until all 2-3 litres are given. This gives a chance for one lot of water to start being absorbed before the next lot of water is given. If you try and give all 2 or 3 litres of water all at once, most likely the majority of the water will just flow right through the pot without being absorbed. It is much better to give a decent, deep watering once in a while, rather than giving little amounts of water often. You need the soil to be evenly moisten from top to bottom, not just a little water around the middle near the stem. The plants roots need moist soil to be able to absorb nutrients and grow. Any dry patches will prevent this from occurring. 400ml is barely enough for a 6-8 inch young plant in a pot that size. I also think you either need to feed her more often or purchase some extra nutrients to boost her, she is showing all the signs of under nourishment and in my opinion and could do with something with a bit more balance. The "terp tea" you are using is ok for nitrogen but has virtually no phosphorous or potassium, both of which are absolutely vital for normal plant health. If you are keen on organics, I can recommend "Bio Vega" made by Bio Canna, or the "Flora Nova" range made by GHE are really good and simple to use, being just one bottle for grow nutrients and one bottle for bloom nutrients. They are also very concentrated, so a bottle will last many crops, making them economical too. Another is Organic Grow and Organic Bloom made by BAC, a Dutch company and again is one bottle for each phase. These nutrients are all good and much better than many others that make you buy multiple bottles to make one end concoction. Also, try and remove any fallen leaves, especially those on the soil surface as they can be a good place for moulds and fungus to grow, which should always be avoided. So, give her a good drink, feed her with some proper nutrients, rather than the "terp tea" which is more of a tonic, and your plant will pick up its health soon enough. Hope this helps,... Organoman.