Yeah the tank is very large for what I have in it, I could get another pair of seahorses and be at a good stocking level. This was my first attempt with seahorses though and I figured I would under stock the tank just in case. I haven't had any problems but since this was a first for me I wanted to be careful.
The powerheads are Koralia nano's, the smallest one they make, which IMO is the ONLY type that should be used for seahorses. Otherwise you risk them losing bits of their tail as they wrap it between the spaces in the powerhead. Honestly there were a couple times when they were tiny babies that I had to help them off of it because they went near it and got stuck to the side from the water being pulled in. I would either have to help them or they would sorta of crawl to the edge and be blow off.
The tank has four of the nano's, the return for my HoB skimmer, the pump for my chiller, and my Rena XP3 return. It's actually a lot of flow but the XP3 and one of the nanos is providing water movement behind my wall of live rock, the skimmer and chiller returns are both at the surface, so it's really just the three nano's for the rest of the tank. The seahorses actually don't mind all of the flow, they'll hang out right in front of one of the powerheads or returns just kind of enjoying the flow and they go "surfing" from time to time where they'll go behind one of the nanos and then go right in front of it and be blown away, then come back for another go.
If anyone is interested in getting seahorses check out
Seahorse Organisation. Keeping and Breeding Seahorses in the home aquarium.. I cannot say enough good things about their Library section there. Tons of great information along with a good tankmate compatibility guide. I did a lot of my research for the seahorses there, they also have a good list of medications to pick up for your horses when you get them just in case on their message board.
