Much Agreed!
My Grandfather helped build a Golf Course in the 20's...he was the head Greens-keeper and MGR until his death, then my Uncle and Father took over, so I've worked on grass since I was 12...they were all Natural Grass-Men who saved ALOT OF $$$$.
Under Normal conditions, GRASS DOES NOT NEED ANY EXTRA FERTILIZER!
My 1.5 acre yard has no weeds....I can go around with a spray bottle or Dandelion tool, twice a month for touch-ups. THAT IS MY ENTIRE PROCESS.
Sixteen years ago, when I moved in, the yard was 90% weeds....I used 2 kinds of Weed-b-Gon in a tank sprayer, plugged the yard a Month later and sewed grass seed....the next year I had a few weeds and bare spots and took care of them....I have been "Weed-Free" since!
Most of my neighbors yards are disasters....except my 2 next door neighbors that wanted to learn the system!lol
I actually think I shamed them into keeping their yards nicer, and then they realized how much easier and cheaper it was to do it this way!
My grass stays at 4 to4.5 inches....I let it go to 5-6 if the summer is Brutal....most weeds will not be able to start with grass that tall. All of my "fertilization" comes from mulching the grass, and plugging 2x a year....the rest is from the air and God's watering!
People that mow grass short do not realize that they will mow more often and weaken grass, this is due to grass wanting to go to seed. That is grasses only concern....to grow and spawn!
If you cut it short, it weakens the grass, grass under stress will not be healthy, it will have poor root systems, weak blades, and poor disease resistance....it also allows weeds to get established.
That's where all the chemicals come into play...having to try to repair the on-going damage you are doing to your lawn.
If you do use a fertilizer after a harsh summer, you need to get A BALANCE SLOW RELEASE NATURAL fert for seedlings...it doesn't take much, you just want to boost it through winter...I like Espoma, it contains exact amounts of balanced natural nutrition (in NORMAL doses) that will all be used up by the grass.
Most store bought or Company layed ferts., are high in Nitrogen only, to make the grass green and grow fast...THIS IS NOT HEALTHY and a lot of the nitrogen (etc) is excess, and just washes away.
But like anything else, people don't want to research the facts for themselves and just listen to "Experts" trying to sell more product and services!
You're exactly right....most of that Algae growth IS FROM lawn treatment...so every time you look at your lake and are unable to fish it, think of all the nice pretty lawns....and the lack of understanding that have them looking like that!lol