How much fertilizer to add into this 9 gallon/34 litre Fluval Flex?

[DD1880]

I have had this scape set up since last February with uns controsoil as the substrate and nilocg thrive as the liquid fertilizer I use! In the beginning I was dosing 2ml once to twice a week and things grew well. But in the last month all of my Ludwigia acruata has stunted or just melted. I’m guessing that the soil has run out of nutrients so I put two seachem flourish root tabs in the soil to hopefully recharge it. Should I be adding 2ml of ferts every day with the new plants I put in? I did have some algae showing up but maybe it was because of the stems stunting? Any advise would be appreciate cause I would rather not loose the new plants I put in which are Ludwigia palustris, limnophilia hipporoides, and s. repens! The thrive has 2.56% nitrogen, .42% iron and other micro and macro nutrients! It also says one pump or 2ml per 10 gallons but the flex is 9 gallons. Thank you for any help!