Personally, I'd never get into any method like that with costs of testing, and, as it ties you to one company's products. I'm sure there are success stories with the method, but I'm more sure that many successful systems have NEVER used it.
In all my years of saltwater keeping, I've been one to do water changes to REMOVE elements that have built up in the water because when you add food and it is eaten and then the waste materials are further processed by the micro-life forms, there are still elements that remain.
It would be interesting to know how they plan on "removal" of these excessive elements, and, if indeed they even test for them.
They are dealing with "Base" elements, not all elements and I find it to be misleading to say that you are going to be able to maintain close to original conditions of the water, especially when not everything in excess is going to be removed with a skimmer and refugium.
In addition, they don't test for ALL elements as it would be prohibitively expensive, and, some of the elements themselves would be prohibitively costly if indeed even available in a form that could be used without adding something else to skew other levels.
IF I were inclined to try it, I certainly wouldn't try it on seahorses as they have VERY specific needs that differ from the needs of a reef tank.
I would just advise you to learn what the needs of seahorses are for best chances of success, before you try this.
One starter page would be by Dan Underwood of seahorsesource.com who has been VERY instrumental in the improved success of keepers over the last decade and more. This one page deals with a specific problem but he notes that by doing what is needed to help prevent it, most other problems seahorse related are ALSO reduced.
Seahorses need water that is cleaner than a reef in terms of nutrients that feed and bed nasty bacteria like, but not exclusively, the vibro species. IMO, bacterial problems are the number one cause of seahorse deaths.
To the best of my knowledge there are no test kits available that tell you when your water is degrading to the point the nasty bacteria are expanding to plague and problematic proportions. This means preventive measures and adding specific "base" elements will not solve the problem.
http://seahorsesource.com/?page_id=888
Dan is gradually adding to his helpful postings on his site so you can check out others as well.
In addition, you can glean a lot of info from the "org", but also more up to date articles on Fused Jaw.com where Tami has spent MANY hours providing the latest information to help seahorse keepers.