All the nutrients and substrate have low price. But the substrate is needed to be rinsed before using and it is not documented anywhere.
I didn't have any deficiency nor excess of nutrients, all tha way the plant was healthy and good looking. But I had to adjust the fertilisers ratio on the flowering stage, because the default manufacturer recommended seems not to be optimal especially with an excess of nitrogen.
Yeah, that second plant looks really sick. Looks like it already had the problem starting from day one. Due to the white spots I would consider thrips, leaf miners or genetic defect. Does not look like powdery mildew to me. Not to dampen your mood, but I think she'll die in the next 2-3 week :(
Definitely keep both of the plants distant to each other. With damage like this, you can't know if its a virus, genetics, insects or just the dog hhaha.
But still, happy growing!
@Herikus, yes, she had that problem from the very beginning, and now I don't really know what to do. Maybe it's a good idea to put it somewhere far from others