To preface this I'm slightly new to high tech planted tanks on this scale. I did high tech iwagumi with HC and hair grass and no dosing with great success, but now I'm trying to go for a Dutch style eventually. I noticed recently my ludwigia sp. red and rotala wallichii have been suffering. I picked up some seachem iron supplement as that was what first came to mind. But in recommendation by a fellow planted tank enthusiast I picked up flourish comprehensive. I'm curious to how much I should be dosing my planted 20 gallon long. Also any recommendations for a perfect photoperiod? Right now I have it 8:30am- 12pm then 4:30pm-8pm.
Your help is much appreciated!