As an experienced aquarist, I’m sure you will do well with seahorses. I like a meticulous way you are preparing for your seahorses and making sure that your new aquarium is stable and well established before you order your Mustangs. It certainly sounds like you’re starting off on the right foot and well on your way to creating a prime habitat for seahorses.
The plans for your 35-gallon hex tank you have outlined sound just fine. Your aquarium will have excellent height which is very important for seahorses. An efficient canister filter supplemented with a protein skimmer should provide adequate filtration for a pair of Mustangs. I would adjust your aquarium parameters slightly, however. Mustangs are accustomed to a specific gravity of 1.0245 and are maintained at a constant temperature of 75°F at the Ocean Rider aquaculture facility, so it’s a good idea to maintain your seahorse exhibit at those levels as well.
As long as the Piscine Energetics Mysis relicta has been kept frozen for the past couple of years, it should still be good to use. Frozen Mysis and spoil our go bad when it is allowed to thaw and then refrozen, but its doors very well when it is kept frozen in a block. Mysis that has gone bad will have a tendency to float rather than sinking as it normally does once its thought, and it may turn brownish rather than the usual pearly white or tan coloration. You can thaw out a small portion of the Mysis and see if it’s discolored and whether or not it floats in saltwater. If it’s colored normally, has no order of decay, and sinks rather than floating, I think it should be perfectly acceptable.
For best results, be sure to enrich the frozen Mysis with Vibrance before feeding it to your seahorses. Among other things, this will ensure that your seahorses get a daily dose of carotenoids, vitamins, and beta-glucan, which will boost their immune system and help keep them healthy.
My old Step-By-Step Book about Seahorses was useful enough in its day, but that was a long time ago. As you know, Bryan, that book is now very badly outdated. It was written well before the advent of captive-bred-and-raised seahorses and therefore applies only to wild seahorses. At the time they commissioned it, TFH was looking for a book about seahorses for rank beginners who may never even have kept an aquarium before, so it was geared very much for novices. And since dwarf seahorses (Hippocampus zosterae) were the most popular seahorses back then, and the easiest ones to feed, it was useful primarily to dwarf seahorse keepers.
In other words, it has nothing to offer the 21st century seahorse keeper. But if you liked the old book, then you’re really going to love my new book!
My new book (Complete Guide to Greater Seahorses in the Aquarium, TFH Publications, unpublished) essentially picks up where my old Step-By-Step Book about Seahorses left off and is devoted completely to cultured seahorses. Fully illustrated, the unabridged version of the new book will be 400-500 pages in length, and it is crammed cover to cover with the latest information and cutting-edge techniques and technology for keeping, breeding and raising the various species of seahorses that are now available to the home hobbyist. I will let you know when it’s finally due to be released. In the meantime, you can always reach me online for help with any seahorse related questions.
Best of luck with your new seahorse setup, Bryan! It certainly sounds like you’re on the right track.