One issue with that chart is that it assumes as the additional lamps are added, they are still lighting the same area
- which is physically impossible of course - look at Sanjay Joshi lighting articles showing the actual area of light dispersion for various light sources for a much more realistic (& accurate) representation 😉
Depending upon how 2 (& more) adjacent T5 lamps are installed & reflectors (& reflector material) used, the increase in measured PAR may be substantially less than twice that of the single T5
(sorry no links as I wasn’t all that interested the first time around when I waded through the lighting literature 🙄 )
I agree that plant mass is low, but suspect plant access may also be a challenge, I’d look to add in any fast growing stem plants (not a floating plant fan as I find them oppressive 😳)
Looking at the substrate area of the tank, I see significant (brown) algae
I don’t see algae crew in the video - add Clithon corona snails, Nerite snails, small blue “mystery” snails, shrimp, otocinclus
Daily water change to lift & remove as much algae as possible - wave your hand just above substrate, plants etc
(George Farmer shows this clearly in his maintenance videos)
Re moving plants - try to do this in the first day or so only, then wait until plants are settled & growing well, otherwise you disturb plant root development & there is a limited amount of energy stored in existing plant stems/leaf structure for these restarts
Looking at your Alternanthera (doesn’t look like A reinicki form I’m familiar with re leaf structure is generally more pointed in both submerse & emerse growth), it’s sending out mid stem roots, so definitely trying, ignore leaf loss, stop moving plant, make sure it has enough gentle flow & space around it, sufficient light, CO2, etc
24/7 CO2 can be beneficial especially if there is significant ambient lighting but also ensure there is good oxygenation as plants also need O to build new leafs ... generally if fish are surviving, oxygen levels won’t be an issue for plants
Surface rippling will prevent/limit surface scum