Can you start up another tank for seahorses? The inhabitants of your 180 are not at all compatible. A nice size tank would be a standard 55.
What fish can I keep with horses and pipe fish?
You are going to be limited to slow, non-aggressive fish that won't pick at them and won't compete for food. I've even had ocellaris clowns attack seahorses. Over the years, I have kept the following with seahorses: orchid dottyback, blue assessor, Hawaiian leaf fish, watchman goby, bicolor blenny, black sailfin blenny, six line wrasse, waspfish. (There are probably some others that slipped my mind, but you get the idea - not all blennies are safe - some pick at seahorses)
Can I do macro's in the display?
Yes, I had my seahorses in a 55 gallon planted tank with many species of macro as well as hardy leathers, mushrooms and polyps. (Still have that tank, but had to move the seahorses because my green wolf eel blenny was looking at them with a little too much interest.)
What are a good starter horse?
H. erectus, H. reidi. Get captive bred, always. Wild caught are challenging, expert only. CB trained to eat frozen mysis start out healthier, less stressed. I like
www.seahorsesource.com if you go with mailorder. A lot of times even good LFS don't have a clue when it comes to seahorses.
I would hold off on pipes until you have a lot more experience with syngnathids. Anectdotally and IME, wild caught animals seem to frequently be symptomless carriers of races of Vibrio that can decimate CB relatives (seahorses OR pipes). Labdoc on seahorse.org is a pathologist and has done numerous necropsies of seahorses that didn't make it. Vibrio is highly implicated in seahorse deaths in captivity.
Another reason to take it slow and keep it simple - seahorses get some really weird diseases that can be hard to treat. I think you can have good success with a seahorse tank, but recommend you start out with just seahorses, then maybe add some compatible fish.
Oh, and for clean up crew, peppermint shrimp are good for cleaning up extra mysis - they control aiptasia and seahorses generally leave the larger ones alone. They will often spawn in captivity, providing a nutritious snack for the seahorses.
Hermit crabs need to be super passive, even little ones have inflicted damage. I only keep scarlet reef hermits with seahorses.
Avoid cleaner shrimp, they stress seahorses by trying to clean them.
Keep good turnover, but nothing like an SPS reef (think lagoon). Direct flow behind rocks, and at the surface. Seahorses are weak swimmers so keep strong flow away from feeding, hitching and courting areas.
Temperatures should be less than 80, mid-70s are best. Some advocate even lower, but IME, mid-70s without abrupt swings are good.
Corals I have kept with seahorses: Capnella, Sinularia, Turbinaria, mushrooms, polyps, zoas, any leather
Avoid - LPS that could trap or eat seahorses (open brain, bubble coral), any aggressive/strong-sting corals, giant clams (they really do close on seahorses, I had this happen in my tank).
Good luck researching and planning your tank.
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