Botanicals are great for fish and shrimp both! . All leaves will add tannins to the water, also found within the tannins are compounds that help by booting immune systems of fish/shrimp or act as antifungals.
There are over 50 cultivars. Magnolia grandiflora is quite beautiful. Ours are harvested after they have naturally fallen, which is important, as some of the sugars have been depleted, and are free from pesticides, herbicides, and pollution.
FUN FACT: Magnolia grandiflora produces phenolic antimicrobial chemicals, compounds called coumarins and sesquiterpene lactones, which discourage predation and grazing by terrestrial insects. Coumarins have known anti fungal properties. We can't help but wonder if these same antimicrobials and antifungals might provide some sort of benefits to fishes in a similar fashion to those attributed to Catappa, but this is just conjecture on our part; we are not aware of any specific scientific study on the matter, nor of the existence of data to confirm this theory.
PREPARATION: We recommend that you rinse them well, then steep them in boiling (ore really hot) water for 10 minutes or so prior to use, and/or soak overnight in fresh water, which will help soften them a bit, and make them more palatable to shrimp, as well as to foster a "biofilm" on their surfaces, which provides supplemental grazing for shrimp and small fishes, and fry. And of course looks cool.
All of our aquatic botanicals are intended for ornamental aquarium or terrarium use only. Please use common sense and take the time to boil or soak all botanicals prior to using them, to reduce the possibility of problems. Always go slow when introducing any botanicals into your systems, so you can judge the effect they have on your fishes and plants. They are not intended for human consumption. DO NOT ING