I was going to write a post about #SharkWeek, but decided that the takeaway can be summarized in one sentence and therefore not worthy of an article. Despite the insipid content and blatant fear mongering, Shark Week does ultimately serve as a force of good by raising awareness of sharks and their importance to ocean ecosystems. Besides that, I love sharks and especially love seeing sharks when diving and getting the chance to photograph them underwater. When you have a 6+ foot shark swimming around you by the reef, you suddenly realize how completely out of your element you truly are, and get a sense of deep respect for the amazing animals.
With that out of the way, let's move on to something more directly related to your reef tank.... purple coralline algae. There is no doubt that purple coralline algae is one of the most desired alga in reef tanks and for good reason, it adds a nice purple coating to just about everything in your tank and makes it look super colorful
This loved and cursed form of algae can be a source of frustration for those that want it and don't have it, and for those that have it and don't want so much of it. That said, let's look at what can be done to get it if you don't have it, what can be done to in crease and maintain it if you do have it, and what can be done to control it if you have too much!
First thing I recommend is that you get your hands on two test kits..... Calcium and Alkalinity. These work hand in hand together and it is essential that you know what your calcium and alkalinity levels are so you can determine if you need to increase or decrease one or the other or BOTH! There are a variety of product available that can help with this. Red Sea has a Reef Foundation Pro test kit that test for both Calcium and Alkalinity as well as Magnesium.
Once you know where your water parameters are in regards to calcium and alkalinity, and have them in the proper range, there are several ways you can go about getting the purple good stuff growing in your tank. You can get some starter algae from a coral frag, a piece of live rock or some scrapings from a friend. You can use any of the specific purple algae products on the market as well. These include Purple-Up, Purple CX and Coralline Gro.
Give it some time and eventually you will start to see little purple dots forming on the glass, the returns in the tank, the back wall and the rock work. Once you see it starting to grow, be sure to keep an eye on the Alkalinity and Calcium levels to be sure they are in the proper range. This will help maintain and grow your purple coralline algae until you have a nice layer of crusty purple stuff all over you tank.
After several months, you will most likely find your tank over run with the purple algae and it can start to become a real nuisance that needs to be controlled! To keep your purple algae in check I recommend using a good scraper, metal blade if you have a glass tank, and a special plastic blade made for acrylic tanks if your tank is not glass. Being proactive and scraping the algae from your tank once a week will help keep the task to a minimum time and save you a lot of tedious scraping work.
To keep the purple coralline algae off your in tank circulation pumps and other removable equipment that is in the tank is easy. Go to your local dollar discount store and pick up a gallon of white vinegar. Pour it in a bucket or bin, then soak the items you want to clean in the vinegar for 30 - 60 minutes. After soaking in vinegar, remove the pump ( or other equipment) and gently scrub the coralline algae off with a tooth brush under running water. The coralline algae will easily come off with minimal scrubbing involved. Be sure you soak your equipment in RO/DI water and rinse well before returning them to your tank.
With a little patience and diligence, you will soon have a beautiful purple crust covering your rock work that will compliment and enhance the coloration of your vibrant corals!
For more detailed information about coralline algae, please refer to this wikipedia article!