Having a 40G already way past the diatom stage, my thoughts.
I have always had 3 mollies, picked lots of plants and structure clean.
Purchased 1 red tail shark, he is a clean up monster.
No corries, pleco, sae's or anything of the sort.
This was not enough, I still had to clean glass every 2 weeks.
Bought 2 nerites to see if they would live in 45ppm of CO2.
All typical bladder and ramhorn, mts didn't make it.
They made it so I bought 4 more for a total of 6.
I no longer clean glass or scrub hardscape with a toothbrush.
Problem for me was how many, didn't want more than needed.
6 in a 40G seems great after 2 months of no cleaning.
100% survival rate so far. They still have plenty to eat.
No cleaning for me.
Forgot to add there are 2 Amano shrimp and about 12 ghost shrimp in there to.
Only visible during flake food feeding times though.
Nerites are also cleaning plants too.
No plant damage either.
At least this is one success story.
Sorry for a long post but I am pleased with their progress.
Truly didn't think it would help much.