Yes, you're going to need CO2 to utilize that kind of lighting intensity. Also you could keep that fixture but substantially reduce the lighting duration to minimize algae growth. The fastest and easiest way to deal with it isn't to get rid of the fixture but to change these two factors and increase the CO2 concentrations in the water column. And of course high a high plant biomass to outcompete algae for the available nutrients. It's a balancing act that demands one to have some experience but it's easier to have higher light and reduce it than to have low light and expect to grow demanding plants...Okay it's been almost a month since I bought Marineland Aquatic plant LED fixture 24" - 36" for my 38 gallon and so far light doesn't cover enough space (which the 36" - 48" should do) and what it does cover has grown some algae the timer is very helpful and can be programmed.
I'm gonna return and search for a low-med lighting.
But I would recommend this for those with either high tanks or those who are experienced with lighting and Co2.
I'm still a novice with lighting as well as plants and so a high light fixture is not for me at the moment.
So can anyone recommend a cheaper LED fixture good enough for Med lighting?
Two of the plants I'm trying to grow are a HC carpet and downoi.