Drooping leaves - Nute burn and overwatering?

Hey yesterday I watered my plants for the first time in about 5 days because last time I overwatered. The first two inches were dry. I put my first dose of nutes, Biobizz Grow, tried to put a small amount but did not have a syringe yet.. getting that today.

First plant shows no nute burn but has droopy leaves.
Second plant (last 2 pics) shows nute burn and droopy leaves.

How can I test the ph of my soil?
What went wrong?
What should I do?

The leaves were yellow before btw, I think a nitrogen deficiency caused that.
Need some help asap!

where's the perlite?

scroglodyte said:

where's the perlite?

Click to expand...

I don't got dat. I might add some broken down stryafoam tho.
I was told that it isn't absoultely necessary but it is recommended to use it.
So, what am I dealing with here and how do I get rid of it !

most likely drainage problems, i'd say water much less put some more holes in your pots if you can, ideally you'd re-pot them in some quality soil, trust me they'll love ya for it...mine did