A Cycling Question

[sphelps]

Sponges, bacteria, coral and macro algae as well as tonnes of critters

Not to disagree but everything except coral and algae listed will survive without light, in fact they don't need light at all to survive and some do better in total darkness such as sponges. Algae you don't want and coral.... give me a break, even in the slight chance of getting something of interest it won't survive. The pros to no light out way the cons.