water is clear, brown algae sticking 2 the wall

when cultivating greenwater u need high ammonia so no water changing until u get it. am i right?

maybe becoz high ammonia my fish is not healthy

if i m right, then wat is the correct way of getting greenwater.

ok let me explain 2 u the way i get greenwater then u slowly point out my mistake

1.i put a so call healthy fish into a 4ft highly aerate tank facing a window with average 10 hours of sunlight daily, feed it hikari wheat germ around 6-7 pellets each time and 4 times daily 2 hours interval.

2.leave the fish in the tank with no water change for two weeks, later the yellow algae will appear.

3.when i see yellow algae appear, i scrub it off with no water change and hope the yellow algae will change 2 green someday.

4.well, i had successfully cultivate GW this way only ONCE other than that are all brown.One more thing, when i got GW, do i need 2 change the water 100% or just 50-70%, when the water goes bad.

Hope u guys will help me, i had a lot of failure and only one success