Yes, you can treat the tank. Here's what I did (from my site):
How to treat your entire reef with Interceptor
After a few months, I observed red bugs in my 280g reef and decided I needed to do something about it. I talked with a few local hobbyists and felt that I had a safe plan of action.
One (large) tablet of Interceptor should treat 400g of water. I removed all the hermit crabs and shrimp I could find in my reef, putting them in a safe tank separate from my reef. They had circulation, a heater and were topped off daily to maintain salinity while in quarantine for their safety. I had live rock in their tank as well so they had something to pick food from as well as places to hide.
I crushed up one pill until it was dust, and mixed it in a cup of tank water. I stirred it for several minutes until it was fully dissolved. I've read that you can heat up the water in a microwave to speed this process up, but found that unnecessary. I removed the venturi tubing leading to the skimmer's pumps so that no air was being injected into the body of the Euro-Reef 12-2. The medicine should travel through all the water, including in any equipment such as skimmers and calcium reactors. I also turned off the two Phosban Reactors I had running (one with PO4 remover, the other with carbon). At midnight, when all the fish were asleep I poured the medication into an area of high flow, and let it kill the red bugs over the next 12 hours.
The next day at noon, I reinstalled the tubing to the skimmer pumps to resume skimming the water. I started up the Phosban Reactor, and that included running 3 cups of fresh carbon in the second reactor. I couldn't find any red bugs in my tank after this treatment. I repeated this 7 days later, and then again 7 days after that. Three treatments over 3 weeks is considered necessary to remove any possible future generations from emerging from the reef to reinfest the corals.
After the third and final treatment was accomplished and the water was safe for the shrimp and crabs, they were added back to the tank and were fine. The refugium was also treated since it is part of the system, and odds are some pods were lost due to the medication. However, over time and with some fresh macro algae added, their population resumed and I see them running around. My Mandarin is fat and happy, as is my Six Line Wrasse.
This is not a treatment you have to fear. And the more of us that do it, the less likely we will share such pests with one another when trading frags. Always treat new coral arrivals (from hobbyists or your LFS) with an Interceptor bath for at least 6 hours to keep your reef red bug free.
*fingers crossed*
Well, the nub you gave me is still alive. Maybe I can get it cleaned up and grown out for you. It only has to survive another 3-5 dips before I'll be satisfied.
