Jack 47, UK grow

This was the second week of the grow. I consider the first 2 weeks, seedling stage, the next week I will start the "true" week 1. During this week I didn't found any major problems, just a few curiosities. Plant A got a bit of a calcium deficiency, it's visible on the photos, it's very little damage, just on the first set of true leaves, not a concern at the moment. Plant B is growing a bit strange, the last set of leaves only one leaf as grown, the other leaf didn't fully grow. DAY 9 - Nutes PH - 6.00 Solution Temp - 19.5 Watering Volume - 5L DAY 13 - Water PH - 6 Solution Temp - 19 Watering Volume - 3.5L Things that need to improve: I wanted to find out what is the correct amount of water to give to each plant, I usually water until I see a bit of water coming from the bottom of the pots, I found out that 3.5L per plant at this stage is definitely too much water for this stage, in the past I've been doing manual watering, but I can already see that for this one I will need to set up some kind of drip system. My TDS meter broke, that's why I don't have TDS numbers yet. I think that the calcium deficiency was caused by me, I don't have a reservoir big enough to mix all the nutes, so I need to mix the nutes in batches, that causes slight differences between the batches, and that may cause problems between plants, I need to get a bigger reservoir. All of these problems will be solved next week. At the moment Plant A is slightly bigger than Plant B. Plant A is about 11cm height, while plant B is about 10cm height