Identify this deficiency/problem! (w/pics)

[Guest]

You can use chemical tests a pain in the ass but dead on accurate. Pens are easy to make mistakes with.

 

[Guest]

I had a look at the Hydro store but couldn't find any chem tests. They hav the truncheon things tho, not cheap :S ... I'll keep looking round for the chem tests u speak of.
Thanx.