Advice? Coralline algae

I'm having trouble growing coralline algae it's not dieing off of the rocks that have it but it's not spreading ammonia, nitrite and nitrate are undetected by my API Master test kit calcium is 420 magnesium is around 1400 alkalinity is between 9 and 11. Tank is 110 tall roughly 160 pounds of rock 40 gallon sump/refugium

--- Auto-Merged, Feb 29, 2016, Original Post: Feb 29, 2016 ---

I should add I also use purple tech purple up

 

I have insain growth in my QT tanks without coral. I believe the lighting plays a part. Being tanks without coral just have a T8 bulb

 

You could try making "coralline smoothies" to speed up the spread.

 

The display tank is almost a month old. All the rock that came out of the old tank is a yr old. We do use the new fluvall sea pro 2.0 led lights. That coral smoothie link will help.

 

I seeded my build with some Scrapings and lr. Still no growth after a couple months under hydras. But am fighting phosphates

 

Watch that purple up. Have heard of people crashing their tanks with high alkalinity. No first hand experience.

 

mine took about 4 months before i seen any,then anything plastic in my tank started to get it.its also very light dependant

 

Light dependent meaning spectrum, intensity?

 

Lighting doesn't matter in my tank. It grows everywhere, except dark places like in my sump, overflows, and under rock. But grows everywhere else. It just takes time. Throw that purple up away.
When your tank needs to be dosed when it gets low on Alkalinity and calcium and you need to dose for those the coraline will start growing. It takes time.

 

ive heard it doesnt grow as well or rapidly under led as it does under t5s.halides grow it even better