If you need to reduce flow around the coral here is a hack
Use those clear fruit containers that contain strawberries or blueberries.
Eat the fruits
Rinse well
remove stickers
Weight it down using sand or gravel or rocks.... this will make it sink
There are small cutouts in these containers already that allow water to pass
You can either allow the coral to free float OR stick the soft coral between 2 pieces of rock (dont crush it but weigh it down
(rock/rubble ---> coral <--- rock/rubble)
If needed use a rubber band or thr surrounding rocks should be enough to hold it in place.
Slowly lower it into the water.
If the frag is small use a rubber band or mesh place the coral on top and use mesh or rubber band to gently hold it in place.
