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Brine as the main staple diet is not necessarly a good choice. From a nutrition aspect. They aren't very.
Brine shrimp have their highest nutritonal value when they are newly hatched and alive. The value drops as they grow. This is why it is recommended only to give them to fish a supplement a couple of time a week. With the rest of the time giving a staple food of some sort. IE pellets, flake.
From experience with blue JD's if you want them to grow fast. You should invest in a good staple food. Ocean Nutrition's cichlid omni flake is what I use to raise all my fry when breeding. HBH makes some really good foods as well, as does OSI. Tetracichlid flake and mini grandules is not bad either.
As for your OW (Old world cichlids, africans) you really should get yourself a good spirulina flake food for them. Then you can feed the tank a few times a week with that. The NW (New world cichlids, the americas) will not mind it at all.
HBH Green40 is a great flake, tetras spirulina flake is also good. You can also always go with Hikari's pellets. The cichlid excel is great for africans as is HBH's African cichlid attack pellets.
Hope this helps.