The plants would be fine without CO2 but would do a lot better with a dirt substrate. Your light intensity is too much unless you can suspend the fixture at least 12" above the water surface. You are using 2 bulbs T5HO light fixture here. They are generally in the medium to medium high lighting.
You should stride for medium to medium low light. Dirt substrate. Some liquid ferts dosing. Dosing excel is optional but would help the plants a lot. If you really going after the low tech, maintenance free setup, switch your light to a T5 or t8 fixtures, 2 bulbs. Or putting a screen over the tank for your t5ho light fixture. And plants some ferns and crypts and anaubis. Dirt substrate may not be necessary as long as you can provide some root tabs.