How many seahorses ?

I would try to stay under 10 to be safe. The less seahorses you have, the more attention you can give the individual seahorses and you'll have less tank maintenance.

If you've never kept them before, I would definitely start with 2-3 captive bred seahorses for a long time until you get the hang of them and learn a bunch, then get more. You also won't struggle with any water quality issues that would occur from feeding a large herd. I have 6 in a 65 gallon with a 30 gallon sump and I'm still struggling to keep the water quality good enough for them and all of the corals.

You should probably join the seahorse forum, seahorse.org. There are a lot of great people on it who give really good advice and it's pretty fun. :)
 
Back
Top