Light. I assume this is LED, here's a link I found if this is the one you have:
https://finsnflora.com/aquarium-led-lighting/459-sunsun-adp-400c.html
My experience with LED is next to zero so I would not want to comment on the intensity being OK or not. The spectrum is given as 7500K which is higher in the blue and lower in the red, so this might be part of the issue. Aquatic plants need red and blue light to drive photosynthesis, and that light has to be of an intensity for the species. Perhaps other members have experience with this light and could offer advice. A Kelvin in the 5000K to 7000K range is ideal.
If, and I say
if, the light is an issue due to intensity or spectrum, plants will have more effort managing than algae, and this is why algae tends to become a nuisance. Algae has no demand for "ideal" light, it can use almost any.
The light duration is OK at 6-7 hours. It would help to get a small timer like those sold for lamps, to have the light come on and go off at the same time each day. This not only benefits plants, it is very important for fish that have a significant relationship to light. You can have the "on" time set to the time of day/evening when you are generally home to view the aquarium. Provided this is consistent, and provided there are several hours of absolute darkness (no ambient daylight or room light, such as midnight to the early morning), this will work well.
Depending upon the number of plants and the species, and the fish load, some form of fertilizer might help. A comprehensive or complete liquid is best, something like Seachem's
Flourish Comprehensive Supplement for the Planted Aquarium. Seachem make several products under the Flourish name so make sure it is this comprehensive supplement. It takes very little.
Floating plants are also advisable; these can shade the light, thus helping to prevent algae issues, and floating plants being fast growing will utilize nutrients more rapidly, which also combats algae.
Snails like any of the small ones (bladder, pond, Malaysian Livebearing) will eat algae, but not to the degree of resolving problem algae. But it is one more positive factor. Never acquire fish intended to eat algae; for one thing. all of the true algae-eating fish have very specific preferences as to which species of algae they will (or might) eat, and not surprising most of them will not touch problem algae species. They also can have very specific requirements as fish, making them problems in themselves due to numbers or size and behaviours. Similarly, never use algicides or any chemical treatments as they will usually harm plants and fish. Resolving algae issues by dealing with the cause is the only safe and effective method.
One picture shows my moss ball, I am unsure if it is the source or not as they both have similar looks and texture.
