I have couple rooting red mangrove propagules in my saltwater fish tank, fertilized via fish emusion. I would like to try and train one into a bonsai, but I don't know what kind of soil/ pot would work for it. The roots are fine and happy being in water 24/7 as is ( however I positioned them by the protein skimmer return, so they get air bubbles, so they don't get too dirty or rot)
obviously none of us here want a non draining soil for our bonsai, but with a conventional soil I think my mangrove would just die. Has anyone heard of a mangrove bonsai? or using a water tray instead of a pot?
I have researched the possibility before, but found no documents on bonsaied mangroves. Therefore, what I say here is only what I can conclude from my research. Mangroves can be bonsaied if the leafs can be reduced. This can be done by pruning. The soil used should be fine and sandy. Keep it in a pot with small or no drainage holes, but if no drainage holes are used make sure you water it with reverse osmosis water.
I'd be careful about "no drainage holes" with sand. You could be asking for a huge (and stinking) mess. Mangroves too, have very large and very few leaves. Growing one out to a 3ft bonsai I can see, but to a size that can be kept in a pot on a shelf, I don't think that can be done. You might, though, try your hand at using mangrove in a brackish mudskipper paludarium. 