Apon entering the Sealife aquarium at Linnamaki there is a notice that you can not use flash to take any pictures of the fish.
I expect if flashes were continually going off then the fish would become rather neurotic. The other problem is that some of the fish are very fast swimmers and they would just go by in a blur.
So how do you oversome poor lighting conditions and fast swimming fish? Well the two things that I did was first of all set the ASA to 800 and this helped with lighting problem.
I also adjusted the EV to +2 and that had the efect of increasing the shutter speed so that I did not need to worry about blurred photos due to quick moving fish or camera shake.
Regardless of making these settings the ASA 800 produced lots of noise on the photos so they had to me manipulated by a noise reduction programme called NEAT IMAGE which does a great job of removing noise from photographs and giving them a certain smoothness.
Then if the quality is still not good enough you can use a old polaroid texture overlay to give the impression that the photos were taken by some old and ancient equipment, and even though there are lots of imprefections most people will wonder how you were able to take such colourful photos with such antiquated equipment.
The feel of a photo is sometimes more important than the photo itself.