All i have read about them is, low flow, no micro bubbles and good water parameters. It is also suggested not to have power heads in the system with plenty of places for the sea horses to latch onto, macro algae works well.
please do a lot of reading before setting up!! and remember seahorses need large aquaria with plenty hiding space !! low lighting ,moderate to low flow ,several live feeds dayly and a large biological filter (remember these fish are predators ) therefore they have very high waste factor!! so a very good skimmer is also recomended!! also make sure you get the richt species for beginners ,id suggest hippocampus fuscus. Also remember to try not place mor than one male of the same species in a tank unless the tank is large enough