Suzi, for what it's worth, I've switched to feeding brine with just two basic products now.
I start with live nannochloropsis (green water) for the first week, and then switch over to using Algamac Protein Plus, which is a powder that I mix in a blender for two minutes.
I use very high density growing of brine so it takes them about 5 to 6 weeks to get them to adult reproducing size.
Probably for lower density growing, I would switch from green water to Algamac Protein Plus after 3 or 4 days as they grow at a much faster rate at lower density cultures.
I could use the Protein plus right off the bat, but for me, importing the product from California to Canada is expensive for shipping, customs and taxation and exchange. (triples the original cost basically) Growing nanno is cheap.
Once a week, I gut load the brine that I'm feeding to my seahorse fry or seahorse adults, with Algamac 3050 which is mostly schizochytrium, a fatty acid which as a powder, stores longer than the Selco emulsion products I used to use.
The Protein plus already uses some of this 3050 enrichment as a part of it's makeup. The major part of the Protein plus appears to be spirulina powder, an excellent food by itself.
It makes my cultures of brine much better by being able to harvest at any time and any size and not have to gut load the brine, as they are basically being gut loaded by the food they eat all the time.
A drawback is that the Protein Plus comes in kilo bags but perhaps you can split portions of the bag for others in the hobby.
You could check with Dan at SS as he already sells small packets of the Algamac 3050 for enrichment.
I also use this Algamac Protein Plus as the only food to culture my rotifers as the density I can achive per container is probably at least double what I can do with green water.
Algamac Protein Plus