Ascidians can be used as indicators of ocean pollution. Microcosmus sulcata concentrates heavy metals cobalt, zinc, chromium and selenium, and Ciona intestinalis indicators iron build-up. Other species accumulate scandium, antimony and some other harmful pollutants.
The original and one of the largest list of DIY reef aquarium project links you will find in one place. The large list of links is almost been totally added into the new format, with the number currently (12/01/2006) being 483.
If you have a link to suggest, then please submit it for consideration. Or if you find one that has expired, then please
me so that it can be fixed. You can also let me know what you think of the new format and if there are any improvements that can be made to the way the information is presented.
DIY Links 
Recipes for food for fish, corals and other organisms within the aquarium system.
Calcium hydroxide reactors for maintenence of calcium and alkalnity levels utilising calcium hydroxide powder. Also called Nilsen reactors.