Calcium Build Up?

I think I'm starting to get a build up of calcium on my tanks glass. What can I do to get rid of it. A cloth or papertowl won't scrape it off. I read some where I may need to scrape it with a razor blade. Any Thoughts?:-/

 

It is coraline! You can scrape it off with your algea scraper. I had let it accumulate on the back glass of my tank but scraped off the side and front. The only problem with that is when you scrape it off it causes it to spread!

it is actually a good thing, however when it starts to get on your glass it is no longer that fun!

 

a old credit card , works pretty well IMO
I use that to deal with coralline, purple encrusting algae , and as long as I dont leave it to long its very easy to flake off using the hard plastic

razor blade scrapers will work, but if its an acrylic tank you need to be incredibly carefull IME

for me a softer plastic scraper used more frequently is a better option.

Steve

 

I really hope it's coraline algae. But it's not purple and I did pick at a spot with my fingernail and it didn't really seem to come off. The credit card is a good idea I just swapped out AAA cards, I'll put the old one to good use tomorrow when lights are on and I can see what I'm doing. Thanks for the input.