I re-introduced myself to the hobby a few years ago and decided to re-establish my “fish only” tank, using the resources I have here on the south shore, i.e. local sand, rock, and sea water. I DID NOT treat anything and I have lost no fish, crab, or shrimp (with the exception to some barnacles during the nitro cycle) to any parasitic disease. In the past year I have added a couple of anemones and they have done well. As I have made the change over to a “reef tank” I have had no issues thus far. I am not recommending that you run down to Wally Beach with a shoveland a bucket, but I felt Nantasket, bing open to the ocean, cleaned itself frequently enough to give it a try. To be honest, part of the reason I did it was to show my wife how “inexpensive” the hobby could be. HA!!!