I read people using them for shrimp tanks. From what I remember, they tend to dissolve faster than oak leaves. I think as long as its fully dried u be ok and of course the leaves isn't sprayed with any chemicals. I use to randomly pick up leaves from my yard for a leaf litter tank. I used dried and fresh leaves before. Never had a problem. As for woods, I believe any hardwood is fine for aquarium. As long as the would doesn't contain saps. I've used dried and fresh woods before aswell
I haven't used the leaves but my 55g planted had an entire trunk and stump from a maple that did not survive transplant. All maples are from the Acer family followed by what ever sp. i.e. vine, green, japanese. You can add to your aquarium after the leaves or woody pieces are dry. The sap will leak out over time if not entirely dry but snails and plecos will consume it with no ill side effects.




I have used these maple leaves in tanks, and in combination with other types.
As said above, I also found they broke down rather quickly compared to other type like Magnolia, or oak.
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But for certain small species like killifish, this worked out well as a loose substrate to breed in, and fry to hide.
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For larger fish they may not be advantageous, as the particulate could plug filters, but all leaves eventually break down after a while anyway.
The maple leaves also don't hold that red color long, and fade to a dull brown or yellow.
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So on the subject of leaves how do ya think apple, mulberry or raspberry leaves would do in a tank? I have all 3 trees growing in my back yard atm and I always wondered how my tanks would look with a leafy bottom.