It's going to be 42" x 30" x 30" with a remote deep sand bed fuge 160 lbs of live rock so should be way more than enough.
As long as you have sufficient ammonia to produce a large biofilter for starting off with a large fish input all at once, just add a couple at a time until the biofilter ramps up after each addition.
I have done it before, but with mixed results. The pipefish and rainfords goby were great. Firefish was a huge mistake-
ANY fish can add pathogens to the system that the seahorse hasn't grown up with. Pipefish especially have been a problem because they are almost totally wild caught while todays seahorses are often true captive bred with little previous exposure to pathogens of the ocean.
Quarantine doesn't eliminate this. Quarantine of a fish only determines if the pathogens it carries are a problem to the carrying fish at the time it is in quarantine. The pathogens are still there and can get to the seahorses and end up being a problem. The pathogens can also cause problems to the introduced fish if it's immune system becomes compromised by any kind of stress.
-much like the pipefish and Catalina goby and pipefish. The system will have 1/10hp chill, open top and cooling fans. Planning to run at 75-76 degree. Alarms at 78-
I personally haven't had any success operating long term above 75° in my eleven years of seahorse keeping, as many other hobbyists have experienced.
Admittedly, some do succeed and it may be a combination of extremely intense filtration systems, above average husbandry practices, and, the susceptibility of the seahorses to any encountered problems.
-I do quarantine, prophylactic treat, acclimate and teach to eat frozen before I and fish to any system. Not saying it perfect because nothing is but so far good.-
Most seahorses sold today in North America are already trained to eat frozen, be they preferred true captive bred or the riskier, cheaper, tank raised ones.
There are so many pathogens that may be carried that you would need maybe a dispensary and a lot of time to be able to effectively eliminate the chances to any degree at all.
-absolutely; zoathids, montipora, and gorgonians are my favorites
Some acceptable to seahorse corals do not survive long term in the cooler seahorse tanks, and, many sps corals do not survive the "dirty" water that is produced by the messy eating habits of seahorses. (selectively eating food pieces, leaving a lot of waste to be trapped out of sight, and, the mastication of food upon snicking it, passing minute particulate matter out through the gills and into the water column)
I only have experience with some of these species. So I'm hoping someone has mixed two or more of these species for more feedback-
The
Tankmates Guide can be of some help to you.
You may have to sign up at the org and wait sometimes a couple of days for acceptance to be able to read and participate there.
-I use aqua planner so every thing can be planned and budgeted. It doesn't have a "plan to add". It only has add to aquarium button

kinda works.-
I'd suggest not getting too close to a limit as seahorses are known to have problems requiring meds that can be costly. Also wise to have a 10g hospital tank with aeration available to set up on very short notice.
Check out what meds most try to keep on hand as time is often of the essence in success here. Also, at least one med requires a prescription and a lot of people have trouble finding a way to obtain this Diamox.
Some ailments may require gut loading the meds into live food which again increases costs of treatment.
I have a page with links at the bottom, written by experience keepers and by perhaps the best known, most helpful breeder in North America, that can give you more insight into seahorse general needs.
Go to the bottom of the page at "
My Thoughts on Seahorse Keeping".