Any photoperiod longer than 8 hours a day is probably going to help algae more than plants, but just reducing the photoperiod isn't likely to make the problem go away. Light drives all plant and algae growth. More light means faster growth of both the plants and the algae. However, algae are never going to have a shortage of nutrients, because they require very tiny amounts. Plants will suffer shortages of nutrients unless some care is taken to dose enough for them - using an Estimative Index dosing scheme will eliminate the nutrient shortage problem for the plants, except for carbon, which comes from CO2.
The higher the light intensity, the more carbon the plants need to be able grow at the rate the light drives them to. That means, the more light you have, the higher the concentration of CO2 in the water has to be to supply the plants needs. But, the fish can only tolerate so much CO2 in the water, so that limits how high you can raise the concentration. If you keep the water well oxygenated, by having good water surface ripple over the whole water surface, and, better yet, by using wet/dry water filtration, the fish will have a much higher tolerance for CO2, letting you raise the concentration even more.
Excel is a usable form of carbon for aquatic plants, but only for relatively low light. It isn't anywhere near as effective as CO2, so adding it when you have a good CO2 level in the tank doesn't buy you much.
Those of us who, like me, have a very limited budget for our hobby, can do best by using only low to low medium light, never high light. That makes supplying CO2 by a DIY system work very well, at minimal cost, compared to the cost of a pressurized CO2 system. As a bonus, it also greatly reduces the workload required to maintain the tank well enough to keep from encouraging algae from dirty water/tank/filters. In my opinion, you should use from 20-40 micromols of PAR unless you can afford the cost and trouble for a good CO2 system and the added maintenance that higher light tanks need.
Maybe some hobbyists enjoy becoming expert algae killers, and spending much of their aquarium time on that aspect of the hobby. I can't recall any of those hobbyists commenting here.
Of course high light tanks can be made and kept beautiful and algae free, and there are many hobbyists who have learned how to do that. If you wish to pursue that path, by all means do it.
Incidentally, a drop checker is a good tool for a relative beginner to help him get the CO2 system adjusted to provide adequate CO2 for the plants, but it is worth very little as an absolute indicator of when you have succeeded at that. Once you learn at approximately what bubble rate, with your system and tank, you need to be at, to get enough CO2 in the water, the drop checker becomes almost useless. The real "meter" for adjusting the CO2 is the plants and your observational skills.