My seahorses are dying!!!

[Teen reefer]

Hello, I resemble caught some sea horses at my local beach and wanted them in my tank but once I have acclimated them and put them in they would spin around at the bottom of the tank and roll around in the sand and than die in one hour and I wanted to know what is going on with them, all my Parameters in my tank are stable and it is low flow and has many types of macro algae for they can grab on to so can someone please tell me why are my seahorses dying???

 

[Doctorgori]

My understanding is wild caught seahorse are difficult, esp to feed ....lets summon @rayjay

 

[ThePurple12]

Do you have other fish in the tank? Might be something in the water

 

[rayjay]

I guess I forgot to click on "Post Reply". I typed out a reply yesterday but as it's not here I obviously screwed up.
Anyway, in the time interval involved, I'd guess the most likely cause to be a difference in the water the seahorses came from and the tank water. Tank water variances can be due to having been set up for a while with insufficient maintenance, or leaching of something from contents. Native water the seahorses came from can vary depending on how close discharges are for commercial/civic drainage and land runoff from farms.
I remember a few decades ago, every fish I added to my mature reef tanks wouldn't survive. It took me a LONG time to figure out that my no water change policy made it so that the existing livestock adapted gradually as the water quality changed, but new fish were hit by sudden conditions they were not used to.
I ended up gradually changing the water over a period of time, larger volumes and more frequently until the water basically ended up closer to natural conditions and then I had no further problem adding fish.