First 1

Yellowing at the bottom is either N deficiency or light deficiency. If you have a really week light, the bottom foliage could just be dying, not a huge problem really. Check pH and add a bit of N. If you know you just have a really underpowered light, then prune the lower foliage.

First, under purple light we can not judge your plant health, take pictures under natural light. Second, I cant recommend enough that if you want to feed without guessing, then get an EC / PPM meter, even a cheap one. It is much easier to recommend a level of PPM. If your yellowing is homogeneous, then it is nitrogen deficiency (lack of grow nutes), if it is more prevalent near the tips and the base still green, then it is potassium deficiency.

Try half strength then work your way up.

I think the newb in me is just being to careful.. More nutes lower light.. More water.

If there is no symptoms of any defficiency, then there is no need to up the nutes. Let the plant grow into the light.

Good work 👍.

Hi, This could be normal because the new grown plantparts have a lighter green. You need to check what happens after you have give them nutrition. Normally 30 mins to 6ß mins after feeding this parts should get darker. If so then you know that you can give more ec or feed them one or two times oftener. gl&hf

If You arenot having defficiencies, then keep doing as you have been. Only up the dose when you see defficiencies

Just keep testing pH and ppms in runoff. Looks like you've got too much N. I also fed the recommended amount when I started. Oops! Itll be fine though, they wont even notice it in another few days. If your runoff has a high ppm, then just used pH'd water for the next couple feeds.