Green Corraline taking over Purple

[squid row]

Background:
My experiment tank is now over a year old. I set up a 20 gallon tank that I had used for freshwater as a learning tool as I was gathering the components for my 72 gallon that I will be setting up in Jan 2017.

The tank started with saltwater from my LFS, dry sand and rock from marco rocks.

I added fish over the last 9 months (1 clown, 2 blue/green chromis, 1 starry blenny, 1 three spot yellow wrasse) and they have all been doing great.

CUC involves countless snails, a few blue legged hermits.

Water changes always done with ro/di, lighting is a PC 65 watt 50/50 and filtration is just a simple HOB filter.

Issue:
I have had nice purple coralline growing on the power heads and glass, along with the shells of my hermit crabs but recently green corraline has started taking over the tank. It is growing on the rocks, where purple has yet to get started. But now it is growing on the power heads and glass and growing on top of and over the purple.

Question:
Is there anything I can do to have the purple end up as the dominant color?

 

[flooddc]

IMO and experienced with my tanks, algae will come and go given time.
you can manually clean/remove unwanted algae. Replace your light bulbs and test your RODI water.

 

[75mixedreef]

I would say to enjoy the diversity. You can give your pumps a vinegar bath to keep them clean and scrape the glass to clean it off there as well, but there is not a whole lot you can do for the rocks. Maybe try a bottle of purple up. I have purple and red coralline and I like seeing both on the rocks, but not on the glass.

PC lights are not ideal for a reef tank. Like flooddc said, consider upgrading them to something more suitable for reef tanks. Purple coralline likes lots of light so it could be telling you something here.