Chris, in your first post you ASKED if that set up would be OK. Now, it sounds like you didn't WANT to be told that it wasn't a good way to do it so I have to assume you really wanted people to tell you it was OK to do what you wanted anyway.
To be honest, that was probably me back seventeen years ago. If you reread my post you will see that I never said it couldn't be done, or, for you NOT do it, I merely said it would be BEST to not start off that way. The general salt water hobby is NOT experience that counts a lot when it comes to keeping seahorses. If fact, Dan Underwood of seahorse source feels that he has a much easier time helping out hobbyists with little to no experience with salt water prior to getting into seahorses.
FWIW, I had MORE years of aquatic experience than you prior to getting into seahorses back in 2002, and I was one that thought I'd be successful due to all the tanks I had at the time as reef tanks and fish only tanks for so many years. When it came down to it, I REALLY DIDN'T HAVE A HANDLE ON IT, and the seahorses were the ones to pay the price while I DID gain the experience needed. It was a whole new ball game from looking after reef tanks and fish only.
When you are researching the needs of seahorse keeping, hopefully you can accept the advice of the many LONG TERM keepers in the hobby MORE than some of the shorter term people that espouse different principals.
Some have succeeded in being successful because they have had the luck to obtain more resistant seahorses that survive in spite of a lack of ideal conditions. They aren't to be faulted because they have no way really to know it unless something starts going wrong. Basically, you stand a much better chance of succeeding if you start in a manner that the majority would espouse over a manner few would recommend. Eventually you would find for yourself what you could succeed doing and make adjustments at that time if you still wanted to try something.
Seahorses, like people, have varying degrees of resistance to illness as some seem to be always in trouble, others never have problems, and a whole range of them falling somewhere in between those points, more to the bad side than good in the case of seahorses. Unfortunately, we never know what the seahorses we buy are going to be like, all good, all bad or a mix of in betweens. I have NEVER encountered ANY other marine fish that could be as susceptible to problems that seahorses have.
There are a lot of different systems being used in the hobby, but some basic principals exist, they just are handled in different ways but in the end accomplish the same things.