Thanks all. The substrate is coral sand. One thing to remember though is coral sand will push the ph to around 7-8. So if your tap water has a high ph, like our in Sydney ... And your plants and fish are used to it, coral sand is ok to use and it will keep the ph stable.
Thank you all very much. It's very appreciated. Im very proud of it and my other tanks. We all know how difficult it is to maintain this interest... But we all know the amount of satisfaction it gives back.