what could be the problem? pics

This plant looks nice but on a few of the bottom leaves brown spots are showing and have been there for about 4 days but have not gotten worse and one of the leafs has been yellow for the same time.
other than that it looks nice :]

what i think the problem is might be fluctuating pH.









the other plant is just a little one thats about 6-7 weeks that just has not grown because my cat got in it and dug it out twice about 3 weeks ago :/.

It looks like there are probs in the root area. How are you watering these, whats the feeding regime you are using.

the little plant im sure has a root problem because it was dug out just as it was rooting.
but i feed every other water and they only need watering every 3-4 days. there is good drainage as well. im also using fox farms nutes grow big and big bloom.

what is you ph like after adding the ff.