Thanks for the response. Collection at Tanjong Rhu .
Will prefer to clear the rocks first . Btw the rocks from coral farm , so it's a pretty gd deal .
Can only release fishes once rocks are cleared .
This how a lazy man change water!
I place the whole bag of NSW on display tank.
I will extract all the displacement water from the sump and discard away.
After that, I will release the bag of NSW to the tank. That's it, simple and fast!