DO I NEED TO BUY A SOLUTION AT STORE OR DO YOU HAVE OTHER SUGGESTIONS
Try a power washer. Check out my before and after pictures when we used our power washer around our house where there was a lot of algae on our deck and on the outside of our house:
Get Purple Power from Walmart or a good cleaner degreaser and wash with a power washer.
If you pressure wash (and I would) make sure to use a fan type tip or you risk damaging the wood surface.
tsp trisodium phosphate
Power wash if it's wood. If it's a composite material (we have trex) I just used a scrub brush and Sal Suds with water.