I am suspecting a nutrient deficiency in my aquarium. I am having problems especially, with my amazon swords, dwarf sag and red tiger lotus. Old leaves seem to be turning brown/red/yellow, and new leaves have a stunned growth with occasional small holes. However the swords still produce runners, but daughter plants don't seem the happiest either. If you have any idea on what the cause/solution to this problem might be it would be much appreciated. Thanks!
Aquarium size: 36 gallons
Set up: Since September 24th, 2017
Stocking: about 20 neon tetras and 1 male swordtailfish.
Lighting: 2◊24w t5HO 6500k, 6 hours a day (almost a year old)
Substrate: Tropica soil, with lava rock underneath in back right corner
CO2: Pressurized, about 1bps. On 1 hour before lights on, Off 1 hour before lights off(Was cut of for 3 weeks due to cyanobacteria takeover... probably introduced via plants. Treated with Ultralife, all gone now).
Water quality (as of today - 2 weeks with no water change)
Dosing: None. Wanted to figure out what the aquarium needs based on how plants will react. I think this will be the solution to the problem if the problem is rooted in a nutrient defficiency.