too much nitrogen?

I am attaching pics and hope they are helpful, sorry about light interference. from what I see, there are small yet noticeable brown curling tips on these leaves. I don't know if the photos show it, but they seem to be both tilting up and down on those tips. I am finding it difficult to measure the pH in my pots (5gal pots small plants), since I read that you wait for water on bottom of pots to drip out and sample that. well it would take an over-saturation to create this so I instead regulate the pH of water going in. which last week was slightly higher than neutral. I brought it down, but very brazenly I decided to shock with a bit lower pH (at around 5.8-6.0) to make up for the higher pH it had been receiving. This leads me to think that I fucked up doing this but this was about 4 days ago, am I over reacting?? god I feel like a new parent!

p.s.
the third photo shows an entire leaf discolored. Im curious as to what people think about it.

ok here's a few new shots without the interference from the bulb. the first depicts the lower leaf wilting, the next is a shot of the whole leaf discoloring, the third shows how the leaves are tilting upwards and downwards.

yes you are feeding it to much.. and no i dont think you should flush it i would wait till next watering and only give it water.. for 2 waterings

thanks, judge my next watering date based by moisture content in soil? The way I was doing it is every two days, and I would stick my finger in the soil about 1/4 inch to feel if its dried out, as a means to tell whether it needs watering. Is that the right method?

Men i use the same pots as u
my plants are way bigger then urs
and i water them every like.. 4 days !
so every 2 days for ur little plants is to much
i really wait until the pots seems light
and i put my finger like 2-3 inch in the soil
that more then 1/4 inch
for sure the top will be dry
it needs fresh air for the air root

In my experience if you want to make your growing a long-term thing, one of the best things you can invest in is a moisture metre. You could probably buy one for under $10 and that will allow you to really probe the soil to determine moisture conditions further down in the soil, especially if you have a larger sized pot. I have had plants die of overwatering and when examining the pot after giving up on them I have found that while the top and sides of pot might indicate really dry soil, the centre can still be really wet - and at a depth beyond which your finger would probe. Because this is the area that surrounds the roots most closely, it increases the likelihood of overwatering.

Brown and curling tips can also indicate over fertilization or overheating from placing plants too close to lights. As your plants look pretty healthy apart from some slight discolouration I would look at whether the plants closer to light are the ones most affected, in that case I'd guess overheating. If they are all suffering equally, you could look to overwatering or over fertilizing as the source of the problem.