How to Grow
Coralline Algae

Original Article and Photo Source: Stan & Debbie Hauter, About.com

Coralline algae looks really nice and covers up the plain color of your live rock.

It is what gives many saltwater aquariums their color. This is also one of my main goal when I started in the hobby.

Coralline Algae exists in a variety of different colors (green, pink, white, purple, red).

It must be physically brought into your tank in order for it to reproduce and populate the various surfaces.

You will need a source of coraline to get the process started. A live rock, coral mount, piece of equipment, etc. will all serve as starter cultures for coraline.

So once you have some coralline algae in your tank....

How do you get it to spread and reproduce all over your aquarium?

Some few steps you can take to help it quickly multiply is by scraping a heavily coraline cemented tank walls and let the particles fall to the sand. Turn off your tank filters and skimmers and only leave your powerheads running.

The water current or movement produced by your powerhead will spread the coralline scrapings throughout the tank. It will then continue to grow. Turn on your skimmer and filter after an hour or so.

Another trick is to take coraline encrusted rock or any other equipment and scrub it with a toothbrush in front of high water flow.

As with everything in this wonderful hobby, coralline growth isnt simple. There are many factors that needs to be considered:

Proper Lighting

Some types of coralline algae prefer higher lighting output, while others prefer lower lighting.

As your tank gets older and matures the intensity and spectrum of light fades. And then at this time, most aquarist notices their Coralline growths actually increases.

But the question still remains, what type of lighting is best? There is actually no single answer.

Here is what Leroy, from GARF has to say.

Coraline algae loves actinic blue actinic light and hates white light. To give your coraline a boost, increase your blue light and decrease your white light.

Coraline grows best deep in the ocean where only blue spectrum light can penetrate. When starting a reef tank, allow the blue actinic bulbs to run 24 hours a day for two weeks.

Water Chemistry

Maintaining excellent water quality also plays an important role in growing of coralline algae. They are calcareous by nature like hard corals which requirs many of the same things corals do in order to flourish:

SG apx 1.024
Calcium
- 350 to 480 ppm
Carbonate Alkalinity
- Between 2.5 and 4.0 meq/L (7-12 dKH)
Strontium
Low Phosphates (Close to Zero)
Low Nitrates (5 ppm or lower)

Regular water changes will keep the phosphate and nitrate levels in check as well as keeping the calcium, alkalinity and strontium at or near their optimum levels.

Using good protein skimmers also goes a long ways towards controlling nitrates and phosphates.

Remember that at first, it will appear as a lime green coating. Wait until about three months for you to see your rocks turn pink, then purple. Naturally, the degree of coloration will vary from tank to tank.