are Magnolia denudata and Magnolia x soulangeana leaves safe for aquaria?

[MacZ]

I don’t live near all the office buildings and sky rises but I don’t live in the country

How about streets? Or industry? City means pollution and this can be relatively high even in residential areas. I sometimes use twigs from the yard, but leaves I wouldn't even get from an average suburb.

Provided they are from a low pollution area:
As biofilm is nothing bad per se it should be enough to take some boiling water and soak the leaves for a few hours.

 

[Samala]

We all have different risk tolerances when it comes to adding items to our tanks.

I live in a suburban area with quite high traffic levels and certainly have runoff into my yard from adjacent land that would include fertilizer, pesticides, and fungicides (lots of heavily managed landscape here). I collect freshly fallen leaves year round from my yard and on my walks. With M. grandiflora it's easier to do since they shed all year.

I don't usually do much other than rinsing or soaking them in water for a bit (with white vinegar if I'm really worried) and short microwave trip to zap fungus or other spores.

The levels of air pollution or contamination the leaves are exposed to while on the tree probably aren't great for our tanks, but indoor air quality in most homes isn't any better and often far worse. I would bet more gets into our tanks from settling on water surface than from introducing leaves.

Plus these are pretty hearty trees and don't typically get chemicals applied to their leaves or canopy for pest treatment or for fertilizer. Unless you're collecting leaves from a managed area that have been on the ground for awhile (say, a public park in downtown area of large metro) I would go with rinse, soak, and enjoy!

 

[Ben Rhau]

If I had access to M. denudata or the hybrid I would probably soak the leaves in a bucket for a few weeks to get them to shed any initial biofilm.

I think a few weeks is a bit extreme. For one, the biofilm is OK, especially if you have fry or inverts in tank. But also, you're losing tannins during this long soak period, which is part of the reason you're using the leaves. Personally, I only soak for long enough to loosen the dirt that's on the leaves, rinse, then dry. If you're worried about pesticides, just don't use those leaves.

-Ben

 

[Samala]

Totally agree Ben, if I was using a species I know is safe (M. grandiflora, etc). The above is just a general approach for plants I have no idea whether they're safe or not, or how intense the biofilm shed will be.

It's all about what your risk tolerance is and how you want to manage it.

Plus, not everyone wants nor needs the tannins.

 

[JoseF]

Totally agree Ben, if I was using a species I know is safe (M. grandiflora, etc). The above is just a general approach for plants I have no idea whether they're safe or not, or how intense the biofilm shed will be.

It's all about what your risk tolerance is and how you want to manage it.

Plus, not everyone wants nor needs the tannins.

I enjoyed this discussion. I have a couple of complex magnolia hybrids which I had never considered using leaves from. I do not need the additional tannins but the leaves are definitely interesting.