Simple refuge without sand?

I temporarily (until I decide what type of fuge is for me) set up a small section in my sump without sand to try and grow marcos. Can I simply put a little live rock in and the marcos algaes and it will grow, or does it need sand to root? Also, would one of the Jalli or coralife type mini lights 18 watts compact be enough to grow the macros, or will I need stronger lighting? Any special additives I need for growing the macros? Thanks so much everyone, you have been a huge help already!

 

The Macro Algae will grow on the rock or on sand and some will grow without either. The Caulerpa Algae will grow roots after a week or two and try to latch on to something. The chaetomorhpha algae needs nothing to grow on it just spreads itself out. Here is a link to a good sight on Macro's I do not endorse them but have purchased from them and they treated me right.
http://www.liveplants.gulf-coast.net/

I do not believe you need too many additives as they filter the water and take what they need. Read the requirements section under the algae pictures.
I would go with a regular grow light on the sump 75 watts and run it 24 x 7 or the reverse lighting of your main tank. I hope this helps in your decisions.
Jim

 

Very cool link, thanks!