I believe you're suggesting adding these supplements to the food as you soak it, right. School is out on this topic. Many people swear by one or the other or both. Many others believe it doesn't really do alot because we often forget the inherent ability of fish to fight off ick or other problems if its healthy & the infestation is light. Personally, I use a UV sterilizer.
What was said about mangroves is true. They are very slow growing, unlike my caulerpa & red halimenia, so their presence is more aesthetics than as active nutrient exporters.
Crabs - don't trust 'em in your tank. Even the ones that are "reef-safe" may not be if you get a rogue
I had a tiny orange one in my LR that I thought was harmless. 8 months later it snipped my pulsing xenias & that was that. Unfortunately, I haven't seen it in months but I think he might still be in there somewhere. Previously, it only ate algae & detritus.
I'm also a late-nighter, since I'm editing papers. Got to get back to work now.
