I went from dino hell with dinos covering 30% of the sandbed and rocks and growing:
To this after 8 days using the method I previously posted.
2 months on, no sign of dinos and the tank now looks like this:
As per another who has posted a method to remove them, it's not short or easy. There will be casualties. You may notice I only had 3 SPS and a few softies/LPS, however those who advised me of the methods did the same with large scale SPS tanks. If you want to know what worked, have a look at my previous posts and if you have any questions, feel free to PM me and I'll help as best I can.
Good luck with your battle. It is winnable.