[*]24" cube tank (about 60g)
[*]live rock--anything to be concerned about with hitchhikers?
[*]A sump (with what kind of pump/intake to the sump? is a Calfo ctc overflow a good idea?)/refugium for propogating yummies for the SHs
A 60 gallon will be great for 3-4 pairs of seahorses, depending on species, and/or 1-2 pairs of seahorses and some fishy tankmates. Live rock, like he said, aiptasia and mojano anemones and corynactis/pseudocorynactis corallimorphs can be a problem with stinging the horses; as can any large hitchhiker crabs, but, personally, I think that the LR is worth the hassle of trying to get rid of the pests. Another thing that comes with LR is bristleworms, and with the amount that seahorses eat, and the slow-pain-in-the-rear-take-their-sweet-time way that they eat, the bristleworm population can get disgusting in no-time. A well set up elevated feeding dish in a lower flow area of the tank will help with that. I use a modified calfo/coast-to-coast (doesn't run full to either edge of the tank). Works fine. You aren't going to get seahorses in your overflow unless you have really high/turbulent flow and/or problem tankmates. I've never had a seahorse in my overflow, and mine doesn't have teeth. Gobies, on the otherhand, are a different story. An external return pump is a good idea to keep the temperature down.
[*]Fan worms
[*]Corals... softies? Or others? What kinds?
[*]Macroalgae... cool... what kind?
Fanworms are okay, but the seahorses hitching to them does upset them, and they may bail because of it. Additionally, if you plan to keep peppermint shrimp to keep aiptasia under control, it has been my experience that the peppermints just add to the irritation of the fanworms, and may actually go after them. Softies and coral without sweeper tentacles are usually okay provided they can handle the lower temperature, lower light, and less direct flow. For me, this has been a trial and error thing and so far, very few things have thrived long-term, although, "tree" corals (kenya tree, etc.) do seem to thrive in seahorse tanks. Try the compatibility list on seahorse.org
http://www.seahorse.org/library/articles/tankmates/tankmates.shtml
As for macro algae, everything is safe, so just add what you like (after FW dips, quarantine, etc.). It is also a trial and error thing to see which algaes thrive in your tank. I would avoid caulerpa sp. for it's tendency to take over a tank and difficulty removing it, but other genus/species should be fine. Depending on the time of year, reefcleaners.org carries a good selection of macros.
Heater/chiller as needed in sump to stay under 74 degrees, etc. depending on breed of seahorse
I
do keep a heater (two actually, in the sump) to prevent large fluctuations in temperature between day/night. It also helps with the other fish, inverts, corals, etc. in the tank. Plus, depending on the species of seahorse you keep, IME some species and specimens don't handle going below 70* very well. On the chiller front, I wouldn't recommend you take any species over 74* if you can help it, 76* at most.
If I do zoas and softies, for instance, can I do T-5's? Do seahorses mind lights?
No, seahorses don't mind lights. They mind the heat that comes from really high lighting, but the lighting itself is no problem.
How do experienced people do flow in the tank? I know it has to be low, so... are CLs good? Vacuuming sand? Have read about the latter, but it goes against all my reef tank experience.
CL's are great. But, you want to split up the flow. No direct flow like you'd do in an SPS reef with locklines, etc. Instead, you'll want to make spraybars/diffusers, that have many different exit points for the flow to really split it up. What I have (which is my return, not a CL) are two 1/2" PVC pipes running vertically down the back of my tank, with 7-10 holes drilled in each (I can't remember) in varying directions to run flow across the back wall, up the side walls, and through the rock structure. Keeps a really good solid flow, especially near the spraybars, but disperses it really well throughout the tank so it's nice an gentle in most areas. You do
not want areas of
no flow. Besides the obvious waste/ammonia/nitrate production of dead spots, it also allows for the growth of pathogenic ciliates and other disease problems for seahorses.
Vaccuming sand - no. I wouldn't. That being said, vaccuming the surface of the sand (i.e. not disturbing the sand, or only disturbing the very finest surface layer) is a good idea. It helps to remove any detritus or algae buildup, and it also can remove any disease organisms growing on the surface of the sand in that detritus, like ciliates, which cause weak snick. It will be less a problem if you use a feeding dish (although that should be cleaned regularly).
Are more seahorses better? Or just more? If you have only one pair, what else can add interest? Corals? Crabs? Shrimp?
More seahorses beyond one pair are just more. They'll interact with each other usually, but they won't do anything any more special if there are more of them (except the males will sometimes display more and/or "compete" for the females) . Crabs aren't a good idea. They like to get the seahorse tails between their pinchers. Take a look at the compatibility list I linked to above for other tankmate ideas. I had a clown goby with mine for 3 years before he passed away this year, and I currently have a rainfordi goby, a scooter dragonette, and a sunburst anthias (the
only anthias I'd even try to put with seahorses - they are extremely passive/timid), plus peppermint shrimp, a fighting conch, nassarius, cerith and nerite snails, macro algae, and a very unhappy patch of GSP.
What about sexy shrimp? They are so cool looking!
Seahorse dinner. Sorry. Maybe in your refugium?
