Flatworms vs Damsel

[Peterski]

I have a flatworm problem on my glass, I don't see any red ones. Just brown and really tiny glass ones. I purchased a Springeri ( Jerry ) Damsel.
How long does it take for the Damsel to start devouring the flatworms ? I see some in the sump as well, should I stick a damsel down there ?

Trying to avoid FW Exit. if i end up going with the FW exit route, how do you see and syphon the FW ? or a 20% water change weekly should be sufficient ?

 

[Tahoe61]

have you tried not feeding the fish for a couple days and blowing the flatworms off surfaces with a turkey baster.

 

[Peterski]

good idea. i am just scared my fish will die from starving. I have a marine betta and a purple tang.
I will scrape off the glass