Angel, I recall seeing photos of your former setups with the Red tiger lotus growing super, and I believe I mentioned at the time that this was due to the warm light you had; light higher in the red (lower kelvin number) was providing more red which red-leaf plants require simply because they reflect red light or they wouldn't appear "red." So there needs to be more of it. Some aquarists compensate by increasing the total light intensity. Amounts to the same thing, the plant needs more red light. It also needs good fertilization. But notwithstanding you did not dose with fert then, your tap water may have contained minerals plus the fish food certainly contains minerals, plus other processes.
A comment on the EI method, it is not meant for low-tech setups such as you and I basically have. To try that in such a setup would be foolish in the extreme. Overdosing with nutrients in an amount which is guaranteed (intended) to be more than will balance the light and CO2 is only asking for trouble. That has to be clearly understood.
I also don't see the need to spend all that money on mega-light, CO2 systems, and continual dosing with nutrients (which must in itself be considerably more than the $60 CDN [prob $45+ US] a year I spend on fertilizer for my three aquaria) with the deliberate aim of providing more than the plants need then removing them with sizable water changes--when we can have 95% as good plant growth without it. Common sense should prevail.
I realize there are probably a couple of plant species I would not have luck with (though haven't bothered to try, since I am perfectly satisfied with the lush growth I have had over 15 years) because of my natural approach. But the fish are first in my aquaria; the plants are there for aesthetic reason plus, and even more so, water quality. And I know they do the job. I am constantly trimming the Pennywort and pulling out runners with pygmy chain swords every week. And I have some plants that have been thriving for more than 10 years in my tank. I am not about to disrupt all this and spend unnecessary money doing it, just to grow one "difficult" plant species.
Every successful and knowledgeable aquarist I have ever read understands that an aquarium is a balanced eco-system. While I do not suggest that going the EI route cannot result in a balanced system, it clearly requires considerably more input by the aquarist and that means the balance that nature can provide simply is being tampered with, plain and simple. The fish need stable water quality to thrive, and the less fussing with it the better. This approach has stood the test of time; for more than a hundred years aquarists had lush planted tanks with no CO2, no fertilizers even, and for much of that time, no electrical gadgetry at all. Wioth some attention paid to lighting and fertilization, anyone can have a beautiful thriving planted aquarium.