thats where i have read conflicting posts. some say it had no impact on their crabs or shrimp. I guess it depends on the strenght of the dosage you administer to the tank.
It can kill off some of your inverts but not all. Here are my notes from when I dosed my 180 tank back in 2004.
After 6 hours of treatment I looked at the tank. Looked over all my acros.
I couldn't find any red bugs, not one. I checked a few acros that had at least 8-10 bugs on one branch. I didn't see anything. Then I checked the rest of the tank. One acro crab on a yellow a. tenuis was hanging on to a branch in a dramatic death display. Wasn't happy to see that guy. I looked at the other acros and could see their crabs moving. So they weren't all dead. I found a few more scarlet hermits roaming around, they looked fine. So I started rinsing lots of carbon.
<p>Shut everything down at 6 hours after treatment. Did a 65 gallon water change on a total system volume of 280 gallons. Threw in about half the 3.65 liter black diamond carbon(about 64 oz.), and two poly filters. Two hours later and still no red bugs to be found. Some of the acro crabs are still moving, my starlets are out and eating algae. I noticed polyp extension on two of my acros that had shown no polyps for months. Nothing crazy but they were out! I'll look at them ay night and see if it looks better
http://cnidarianreef.com/G180/images/logs/DSCN3873.jpg