First on the cloudiness, from your description this is a bacterial bloom. Cleaning--or even moreso, replacing--filter media often causes this, as a balance of various bacteria is suddenly gone, and new bacteria suddenly appear. Bacteria here includes all species, not just the nitrifying. Water changes make this worse sometimes, because the new water has dissolved organics and with the dechlorinator the bacteria can rapidly multiply to consume the organics. This is common in new tanks especially. You might find a bit more detail here:
If the lack of nitrogen was meant to be linked to the cloudiness issue, I doubt it is. As for these fertilizers, i will leave it to those with far more experience with these than I have. With my natural (low-tech) planted tanks I never dose on this scale with macros. My only comment would be that they must be balanced with all nutrients (including carbon) and light. Otherwise, they will only feed algae.