I can't get the
www.greenstouch.com site either.
Briefly:
For photographing fish you just about have to have a flash. A built-in flash on the camera is difficult because you have to avoid reflection back at you from the glass (shoot at an angle), and the fish do not look natural illuminated from the side. For good pictures you have to have a flash sitting on top of the aquarium attached to the camera with a sync cord. Only the high-end digital cameras are equipped to do this.
Plants are a lot easier. You need a tripod because you will be doing exposures of more than one second in most cases. You want the lens stopped down (f16 or f22) so that you have good depth of field (things in reasonable focus nearer the lens as well as further away). You don't want to use the high ISO (light sensitivity) setting, because you tend to get grainier pictures with poorer color. An ISO setting of 100 or 200 usually gives the most pleasing results. For all these reasons, you may have exposre times in the 10 to 20 second range.
Before taking the picture you want to look carefully to see what is reflecting back at you from the glass of the aquarium. Lights on other tanks? The shiny aluminum legs of your tripod? You may not notice these reflections when you take the picture if you are not looking for them, but you will certainly see them in your picture. For the tripod leg problem I use a three foot by five foot piece of black cloth and drape it over the legs of the tripod. More serious tank photographers than I have a large piece of black cloth, something like five feet by five feet stretched on a frame with a small hole cut in the middle for the camera lens to poke through. This is the best way to eliminate all pesky reflections.
Also clean the glass of the aquarium. Otherwise, you may notice in your picture marks from dried water drops and other miscellaneous crud.
With a digital camera, learning by trial and error is not as bad as with a film camera.
