Low light macro algae tank?


Junior Poster
Oct 15, 2010
I'm wondering about the lighting requirements of a marine 'planted' tank. I am upgrading my 30 gallon FW tank for a 60 gallon and I was thinking about using the the 30gal as a SW algea tank. It's got fluorescent tubes, about 2Wpg. I was wondering if I can grow some of the macro algae with the lighting it already has. I know this is nothing like reef lighting but seeing as people use algae in their refrigerium I'm thinking it might be possible even if the results are not so spectacular as some. It's hard to find info on this. Any input would be great.
Last edited by a moderator:


Prolific Poster
Dec 23, 2008
British Columbia Canada
What are your bulbs/fixture? How deep is the tank?
It can be done but you need to be selective on your macroalgaes. reds prefer lower lights, green medium and browns high light. Although some species are exceptions to this rule.


Lifetime Charter Member
Lifetime Member
Jun 21, 2009
Surprise, AZ
A Salty Salad, I See


The 2-watts per gallon are going to be on the low end, certainly.;)

The red coralline algae give you bit of a break on the light, the less light the more. Along with macro and micronutrients, you will need to maintain a minimum of 450-ppm Calcium.:D

I would think one of the Rhodophyta- red algae would be wonderful, perhaps
  • Bossiella spp., a genus of coralline algae, very tolerant (comparatively) of water conditions.
  • Bossiella californica schmittii, with the reproductive "bumps" (conceptacles is the prper term) on the face.
  • Bossiella sp. (Silva) a nice, rather forgiving Red Algae.

Red Gracilaria Algae might like a bit more light and is readily available as it is aqua cultured as fish (human as well, I gather:eek:) food.:rolleyes:

Lithothamnion prolifera, any Lithophyllu spp., I suppose these grow pretty much everywhere, even hundreds of meters deep.:)

If you are able to increase the lighting a bit, maybe another 20 r 30 watts of actinic lighting would be nice.

  • Peyssonnelia sp., Burgundy Crust would be worth a try, might be under the bit more light category.

If all else fails, Porolithon pachyderm, Reef Cement will take on the shape and texture of any substrate or anything that happens to be the tank.:cool:

I hope this helps…:gw

Tom Barr

Staff member
Jan 23, 2005
3w/gal of T5 lights are good, the GE 6500K are decent for the $$.