Welcome to TPT Witchlizzard!
New tanks typically go through periods of algae problems. Frequent water changes (2-3x week) for the first few months can help quite a lot with this. Unfortunately, that's a lot of work you obviously don't want to do.
I am not familiar with the light you use. From the link you provided it seems to be very high in the blue spectrum since it's designed for reefs. The par readings were really high for a planted tank, 600 PAR. I am far from a lighting expert but high light would be my first suspicion. Hopefully Hoppy will chime in on your lighting. He seems to be the resident lighting expert. Below is a quote from a sticky in the lighting section
. It's a good article on lighting planted tanks.
Low light - 15-30 micromols of PAR - CO2 is not needed, but is helpful to the plants
Medium light - 35-50 micromols of PAR - CO2 may be needed to avoid too many nuisance algae problems
High light - more than 50 micromols of PAR - pressurized CO2 is essential to avoid major algae problems
Many freshwater algae can be caused from unbalanced nutrients. I realize in the reef community a 0 Nitrate reading is good. However, in the planted tank it's an invitation to a host of problems. Nitrate generally provides nitrogen, which is one of the three macro nutrients for plants. The other being phosphate and potassium. Believe it or not we want those in a planted tank. So I would guess you also need to consider "dosing" your tank with nutrients as well. Since you're not interested in high maintenance lower light and nutrient dosing will provide less growth.
The three main things to balance in the planted tank are light, CO2 and nutrients. Since you want low maintenance I would avoid CO2 injection. Instead use generic Excel, Glutaraldehyde. It can be purchased as Metricide, a medical cold sterilizing solution.
For the nutrients consider dry fertilizers. They are very inexpensive and easy to use on such a large tank. The frequency of water changes and amount of light dictates the amount you need to dose. Even with low tech tanks maintaining non-limiting nutrients is a good idea. Here is a post
about that concept.
It may also be helpful for others if you provide the model number of your lights and what type of substrate you are using.