Way too long of a photoperiod. You should have started around 6 hours then ramped up to ~8 hours over the course of about 6 weeks.
You are also barely giving them any nutrition, especially with a 12 hour photoperiod. Excel is a carbon supplement. Envy is kind of like a daily supplemental vitamin but without providing actual fertilization (micros and macros), they aren't supplementing anything. Look into the EI method of dosing and buy some dry ferts. $15 bucks will cover all nutrients and last a long time (probably more than a year) with a low light setup.
Eco complete is an inert substrate. It doesn't provide nutrients but it holds onto nutrients that you add (like root tabs or liquid/dry ferts).
Reduce your photoperiod, add some actual fertilization, and start doing weekly 50% water changes at a minimum. The current state of your tank is like running on a treadmill for 12 hours straight it the only nutrition you get is 2 slices of bread and a glass of water. Even the strongest of runners would eventually "die" if that's all they were given.
Light dictates everything a plant does and without a proper balance of light, nutrients, and co2 (gaseous co2, not excel, but excel can work very well in low tech setups not running pressurized co2) we run into issues.
Honestly, your tank could probably do without the led and just run the T8. Leds have the potential to produce very strong light (not always the case though). Don't underestimate the power of led. You could also try and run just the led. Either way, you have too much light for too long without providing your plants with enough nutrition to conpensate for the intense lighting. However, none of your plants need that amount of light so in return, they don't need much nutrients to begin with (which they take in slowly anyways).
You are also barely giving them any nutrition, especially with a 12 hour photoperiod. Excel is a carbon supplement. Envy is kind of like a daily supplemental vitamin but without providing actual fertilization (micros and macros), they aren't supplementing anything. Look into the EI method of dosing and buy some dry ferts. $15 bucks will cover all nutrients and last a long time (probably more than a year) with a low light setup.
Eco complete is an inert substrate. It doesn't provide nutrients but it holds onto nutrients that you add (like root tabs or liquid/dry ferts).
Reduce your photoperiod, add some actual fertilization, and start doing weekly 50% water changes at a minimum. The current state of your tank is like running on a treadmill for 12 hours straight it the only nutrition you get is 2 slices of bread and a glass of water. Even the strongest of runners would eventually "die" if that's all they were given.
Light dictates everything a plant does and without a proper balance of light, nutrients, and co2 (gaseous co2, not excel, but excel can work very well in low tech setups not running pressurized co2) we run into issues.
Honestly, your tank could probably do without the led and just run the T8. Leds have the potential to produce very strong light (not always the case though). Don't underestimate the power of led. You could also try and run just the led. Either way, you have too much light for too long without providing your plants with enough nutrition to conpensate for the intense lighting. However, none of your plants need that amount of light so in return, they don't need much nutrients to begin with (which they take in slowly anyways).
