This week saw topping of the plants as the first step in creating a manifold. Plants had grown until the 6th node was emerging, and cut down to three. The growth tips from the first and second nodes were removed, as well as the leaves from the first node. The growth tips on the third node were perhaps a little small, but after only three days had grown dramatically.
To support this growth, the plant used massive amounts of nutrients. Over the two days following the topping, the plants developed nutrient deficiencies. The pH had dropped to 4.5 in the reservoir, and thus I suspect a calcium / magnesium deficiency. There is some damage to the leaves from the rapid drop in pH. I added 2 ml/L of Hortimix B, which is a calmag nutrient. This seems to have arrested the deficiency, but the back-right plant still shows early signs of calcium deficiency on the leaves coming off the third node. I have decided to increase the nutrients to 6 ml/L and 7 ml/L of A and B respectively to compensate for their increased rate of growth.