What kind of salt do those take and what kind of ratio? A friend of mine got some of those for his salt water tank. He said they work for fresh water but everything Ive read on red mangroves is that they live in estuaries. Dont feel like killing them in my tank (which is fresh water), if i wanted to throw money away to kill plants I could find faster ways than that.
Tomo, From what I understand, Red Mangroves are brackish to full-blown salt plants. If you're interested in some truly freshwater Mangroves, Black Mangroves are the way to go. I've successfully (so far) raised Black Mangroves, from seedlings to saplings, in my freshwater tank for almost 1.5 years now.
Kel, Light and Ferts! I use API root tabs in my planters, I'm not sure they're effectiveness in salt so ask around, but I can't imagine them being a problem.