It doesnt look like bugs to me, it looks like damage from the leaf being squeezed or pinched or whatever the fuck. Watch CLOSELY. If no more holes appear, youre good. Look under the leaves too, most pest hide under the leaves. Your pH and ppm look spot on to me. I think youre doing everything right. I highly recommend you start some LST (low stress training) and start bending the taller branches down and out to open up the middle and other nodes as well. Just use soft garden ties, pipe cleaners, anything that wont cut into the plant and start making those ladies SPREAD EM (sorry i couldnt resist making an adult joke)
In case you havent done any training before, its not that complicated. First, just spend a minute or 2 with the plants and looking at them to get an idea of how the plant wants to grow and which branches to bend. Then when you pick a branch, wrap your little wire tie/pipe cleaner around the branch and gently bend the branch until you start to feel resistance and then tie it down. Do the same thing with any other branch you can/that needs it. In a day or 2 the tips will be turned back up to the light again and youll be able to bend those branches a little more. I bend them right down flat so that there are 6-8 branches off the main stalk that bend out at almost 90° angles and then turn up toward the light. Each branch is then topped 1 last time giv8ng me 12-16 tops per plant. The great thing about manifolding is that all of your work is done at the front end. Once you get it trained, tied down, under a screen, defoliated and then topped. Once youve dont that you pretty much just leave them to flower. Rearrange buds around week 4 of flower but thats it. Hope this helps.
DwJ
. Mark my words, its only a matter of time until someone does something really fucking stupid and it sets off the powder keg.
i need another one and as soon as ive acquired the funds i will be buying it. Notice in the spec sheet, in the description area, its described as a "medical plant light"? 
