Premium Member
I'm in the 28th day of cycling a marine tank that will probably end up a hybrid with some low light corals. Money is a problem so lighting is normal output fluorescents (120watts on a 55 gallon tank). I started with crushed coral as substrate before I learned about live sand. My question is can I add live sand to the crushed coral directly in the tank, or should I get a small hang on refugium for sand ,some critters and macro algae? I really don't want to remove the crushed coral but I do want to control nitrate. I have 1 piece of live rock and will add more soon. By the way nitrites are still way up and ammonia is 0. I'm running a wet-dry with bio-balls and a counter current protein skimmer.


Tom Brady
Hi Tom,

I really don't know how to advise you. If you want to keep the crushed coral you will get a lot of life in it, along with a lot of detritus and almost no nitrogen reduction capability. You will need a LOT of extra filtration of one sort or another. I would not advise that you set up a sand bed in a refugium because I think it will be fruitless, I doubt you will be able to get the filtration you need from small bed.

With a light bioload, you may be able to get by with your present filter.

Good luck!!!