I can't answer you're particular question because I am a debutante in the hobby, but I will tell you my own issue which is similar. Set up a 24 gallon cube a month ago; Flourite substrate with volcanic pebbles on the bottom, CO2 through a GLA regulator (1-2 bps)/Finnex Ray2 light both on 10 hours a day, full planting of dwarf baby tears up front, hair grass in the middle and variety of taller plants in back. Didn't use ferts for a week or two and my plants started to look like yours, yellowing and some spots on leaves etc. Based on recommendations on the planted tank forum, picked up clay capsules with macros and Thrive all in one liquid fert from NilocG. First couple of weeks didn't add anything but the clay capsules below the rooted plants (before planting). Couple of weeks in I added the Thrive as directed...next day hair algae hanging all over the place. Over the last two weeks I have altered dosing and CO2 (cutting back both), changed out the water and cleaned off the algae twice, used H202 on the large rocks and baby tears (under water) to oxidize remaining algae...and tried again. I'm now down to one squirt of Thrive (recommended dose is one squirt per ten gallons, so I'm now down to less than a half dose) and also cut three times a week as recommended down to twice. I can't completely get rid of the algae but is is less than before. Chemically my nitrites are spiking and have been for over a week, and nitrates are starting to rise as well. I"m convinced the capsules, in combination with the Thrive in the water column with plants that are not fully grown...is simply too rich for my tank yet...particularly in light of the fact the tank has yet to fully cycle.