coraline growth on plastic

[onefishtwofish]

I have a 75 gallon reef ready FOWLR, about 5 months old. I started with some cured live rock, as well as some base rock. The base rock looks good and is turning purple and green. The back wall of the tank is black and I've been scraping it to keep it clean. How do I get coraline off of the powerheads and the overflow box in the corner? It seems to stick really tight to plastic surfaces.

 

[scsinet]

Kent Marine makes a scraper called the Pro Scraper. Use an acrylic-safe blade in it. That works about the best, but getting coraline off plastic is no easy task.
You can also remove the powerheads and maybe even the overflow box and soak them in vinegar for a few hours, rinse well, and return to the tank.

 

[nano reefer]

i just use a old gift card that i got a few years ago that has expired and is worth nothing now...