Benefits of Macroalgae?

I've read off and on about the benefits of macroalgae, but some of what I've read seems to indicate that you need a whole of it to see any real benefits (other than if you are using it to provide a home for bugs).  Has anyone come across any sort of rule of thumb that says based on the size of your tank and sump how much macroalgae you should have for it to be beneficial in any material way?

To me, it almost seems like people who buy houseplants for their home based upon the beneficial effect of their adding oxygen to the home.  A couple of houseplants here and there aren't going to really add any benefit in the long run.  Is this the same way with macroalgae?

Do any of you have a separate tank (in addition to your sump) that is plumbed with your tank and just houses macroalgae?  If so, in what order is your plumbing?

Edited by Molli - August 04 2014 at 3:21pm

I have a 90 gallon macro algae refugium attached to my 60 gallon display and 75 gallon sump.   Main pump tee's off with one line going to display and the other to the 'fuge.   Both drain into sump, then through skimmer before hitting the return pump again.   I love the amount of diversity I see in a tank with a lot of algae.

mine ins't running yet, but my system will have a 120 gallon display, 45 gallon frag, 40 fuge, and 70 gallon sump. I'm hoping that this will eliminate the need for carbon dosing because of additional nutrient exportation(along with skimmer) also great place for the bugs that benefit the whole system. the fuge will have a variable pump to control flow and also run an opposite but overlapping light schedule to help with ph swings   

Aloha Molli,

In my experience, the benefit of algae in the system is not limited to just Macroalgae and not limited to it's growth only in the Refugium. The old adage, "Every bit helps" also applies here. Coralline Algae and the soft algae that grows on the glass can be just as helpful to biofiltration as a bunch of Caulerpa or Chaetomorpha somewhere in the system.

I have found that most fish and inverts appreciate the cover and food source provided by algae growing in the aquarium display. It's not necessary, but I love the look. Not everyone loves the look and that's okay. For me, fish seem to fare better when they are introduced into an environment with a growth of algae. The pics below represent fairly extreme algae environments. (An algae "forest" doesn't have to be that dense.)

The intensity and photoperiod of light shining on the algae makes a huge difference. Algae growth can be greatly accelerated with better lighting which covers a wider range of the natural spectrum. The "$15 Home Depot Special", a 75W equivalent Daylight color, twist PC bulb in an aluminum Cone Reflector is probably the best bang for the buck when it comes to Refugium lights.

A longer photoperiod also helps to a point. Algae does need sleep time. A minimum of 6 hours seems to be healthy. I usually run the Refugium Light from 9pm to 9am so it overlaps the display lighting.

The benefits of a Reverse Daylight Photoperiod in the Refugium lead to better health of the entire system. See RDP Filtration in this issue of the Sea Star: http://www.utahreefs.com/SeaStar/wmasSeaStar02Feb.pdf

Lastly, some hobbyists may have heard of Caulerpa going "sexual" and melting away in a day. In my experience this happens mostly when it has been starved by insufficient nutrients. Placing it upstream of Chaeto and ahead of a Skimmer help prevent this problem.

Hope this helps.
Mark  (an algae lover)


Mike's photos make the ordinary look extraordinary, don't you think?


Gold Sargassum and green Caulerpa add contrast to the white sand and clams in this suspended reef.


The YT is happy and content even though it was just added a day prior to this pic.
The pollution created by ~50 clownfish is easily handled by the Caulerpa enhanced biofiltration.


The Christmas Wrasse soon doubled in size thanks to all the bugs growing among the algae.

I will also have my calcium reactor drip into the fuge to help disolve the co2. Should help with ph swings there too