You’re very welcome!
Freshwater dips are administered primarily to cleanse newly arrived fish from any ectoparasites they may be carrying. The freshwater dips also help eliminate hydroids, but are not 100% effective in that regard, since it is believed that, at certain stages of development and in certain phases of their life cycle, some hydroids can survive longer in freshwater than the seahorses.
in any case, prophylactic freshwater dips are not a good option for feather dusters other delicate invertebrates. Invertebrates in general should never be dipped in freshwater. Subjecting snails, tubeworms, cleaner shrimp and other decorative shrimp, starfish, sea urchins, etc., to a freshwater dip will likely result in their demise. In the case of shrimp and starfish, you can literally watch them fall to pieces in the dipping container as they autotomize in response to the osmotic shock. You are quite correct in suspecting that feather dusters would not tolerate a freshwater dip, Michelle. If they were dipped, feather dusters would probably drop their crowns, abandon their tubes, and crawl off to die. So let’s avoid that…
There is no safe way to pretreat feather duster worms and other senstive invertebrates to make sure they are free of hydroids. Basically, anything you can treat them with that would kill the hydroids would also prove fatal to the feather dusters. So when you add them to a dwarf seahorse tank — and they are one of my favorite tankmates for H. zosterae — you are taking a calculated risk that you won’t be introducing any hydroids along with the feather dusters.
I’m willing to take that chance because the risk is fairly minimal. By the time feather dusters reach the consumer they have been transferred from the collector to a wholesaler to a retailer, and then kept in separate systems at every stop along the way, none of which received feedings of newly-hatched brine shrimp or any other suitable planktonic prey. If any hydroids were present when the feather duster worms were originally collected, it’s unlikely they made it through all those stops, unfed for an extended period, and in fairly barren holding tanks, to accompany the feather dusters into your aquarium. There’s always a chance that could be the case, but I for one am comfortable taking that slight risk.
In case you haven’t already seen them, there have been a couple of other discussions on the Ocean Rider Club message board regarding dwarf seahorses that you might also find to be of interest, so please check out the following links when you have a chance. They discussed different aspects of keeping dwarf seahorses, including suitable tankmates:
Click here: Seahorse.com – Seahorse, Sea Life, Marine Life, Aquafarm Sales, Feeds and Accessories – Re:Setting up my very firs
Click here: Seahorse.com – Seahorse, Sea Life, Marine Life, Aquafarm Sales, Feeds and Accessories – Re:Dwarfs – Ocean Rider Cl
Click here: Seahorse.com – Seahorse, Sea Life, Marine Life, Aquafarm Sales, Feeds and Accessories – Re:pixies – Ocean Rider Cl
Best of luck with your new dwarf seahorse tank, Michelle!