There are many colors and sizes of trumpet snails, during the day they normally live buried in the substrate eating detritus. Their burrowing helps tp keep substrate from compacting, and going anaerobic. Right after the lights go on you may find them clinging to the glass eating algae, but quickly drop into the substrate during the day.
I don't find them problematic except if they get caught in a impeller, and there, they can do damage.
Many cichlids eat them.
When my tanks would get overrun, I would drop in a couple Paretroplus (a genus of cichlids from Madagascar), and within 48 hours the population of snails would be decimated.
Snails are the main diet of these cichlids in nature, and if the snail is too big to crush, their can opener like teeth easily extract the snail flesh
Are Paretroplus a substrate spawning Cichlid species?
If so? Yikes!
Would definitely NOT want a set of those can opener-like teeth going at my fingers, in a tank with a pair of fry-protective Paretroplus in it!
I like the snails in my current tanks, I’ve been Harvesting them and adding to the 125 that has a Cyanobacteria issue I’ve been battling. I’m hoping they don’t cause any trouble in The sump of the new tank I’m setting up.
from the tanks setup I kept nitrates sub 10ppm (pre water change) with 60% changes and it took over (the tank was a converted salt setup that was out of control covered in it, I think I should’ve ran more than 2 bleach cycles ) It seems to be decreasing now with less light and less water changes, but I have considered abandoning the plants in the tank so i can just leave the lights off. My 3 other planted tank set up at the similar time has no algae at all, it’s definitely frustrating.
Remember than cyanobacteria are not really algae but bacteria. You need to get the fertilizer just right and test/dose often with fast growers. It is a delicate balance to have enough nitrogen/phospate (relative to each other and overall) to feed the plants without impacting the fish health.