Thank you all for your advice since i have set up my tank.
I finally decided to get rid of the coral, shell substrate and replace it with sand, as you can all imagine in a 6ft tank that holds a 1000litres, that it is not a small job.
I am very happy with the finished product and have only one concern, the sand is very fine, probably the same texture of icing sugar, and some time during the night one of my pumps slid down the inside of the tank and preceded to blow a jet of water into the sand at 1200 litres per hour as you can imagine i was not impressed when i got out of bed, checked the tank, (first thing i do every morning) and could not see an inch into the glass.. I think my fish may still have sore eyes lol..
OK question, tank is now beautifully clear, do i need to be concerned about how the fine the sand is and do i need to replace it with a courser sand.. and all my really cool green algae has died off, and is now just starting to come back, This is not due to the sand storm as it happened before i changed the substrate, is this normal for a just cycled tank, as i thought i went through different cycles of algae until i got the good green stuff
and then i thought it just stayed?
anyway thank you all in advance and i hope you can help
kindest regards kell