What is this purple stuff growing on LR!!!!!!

[lionpicasso]

On my live rocks i have purple (i assume algea) stuff growing on it!!!! looks pretty. was wanting to know what would help it grow. and what is it called.
Thanks

 

[jtoliver]

If it is hard, it is corraline algae and that is something that you want to grow.

 

[big dave]

I smell a newbie! Welcome to the board! Coralline algae is a sign of an established and stable tank. If you want it to flourish, keep your pH stable and keep your alk. and Ca levels up. This can be done by several ways but I favor ESV B-Ionic which is a 2 part alk/Ca buffer. If you keep 2 of the 3 levels i mentioned in the proper range, the other will stay up also. Just my 2 cents. Good Luck!

 

[fishfreek]

I keep my cal in the 450ppm range and shoot for 3.2 meq/l for alk. hth

 

[starfishjackedme]

I add kalkwasser through my top-off unit to keep calcium levels up. It makes the purple grow