Living in America...

[connorlindeman]

I use Oak leaves that I gather near my house. I collected a large bag last year. Still, have a bunch.

 

[Magnum Man]

So I've never used dried leaves in my tank... assume they all kind of vary in time when they become indistinguishable... but how often do I need to replace them, or add new ones, in general??? 2-3 months???

 

[connorlindeman]

So I've never used dried leaves in my tank... assume they all kind of vary in time when they become indistinguishable... but how often do I need to replace them, or add new ones, in general??? 2-3 months???

They will break down over time. You should not have to remove them. Just add new ones as needed.

 

[WhistlingBadger]

So I've never used dried leaves in my tank... assume they all kind of vary in time when they become indistinguishable... but how often do I need to replace them, or add new ones, in general??? 2-3 months???

For me, once the leaf membrane breaks down I remove the stems because they look ugly. But that's just an aesthetic thing.

 

[FranciscoB]

I have used a number of different types of leaves in my tanks over the years. I have never paid a penny for any of them, as I have been fortunate enough to have access to clean, free leaves in the various places I have lived. I have used maple (and sycamore), oak, almond, avocado, magnolia, and others. I only use leaves from my yard(s), as pesticides and pollutants can indeed pose serious problems.
All seem to work similarly, but I prefer the larger, sturdier types, which have a coriaceous cover over them. For instance, oak and magnolia are far more durable (and superior imho) than maple. For the last years I have used exclusively Magnolia grandifolia leaves from my backyard, and I like them very much.
I don't do it for pH manipulation (their effect is minimal if any), nor for 'softening the water' (they don't really do that). They do stain the water a bit, add natural complexity to the tanks' habitat for fishes, and in my opinion they have minor antiseptic properties. Cories love to play among them, plecos rasp them, and other fish nibble on them and or hide about them.
I add ~8-12 large Magnolia leaves to a 6' tank, and replace them about every other week. Usually I don't replace them all at the same time, just the ones that seem more "used-up". I do remove what is left over after some time, but that is a preference on my part, not a critical issue.
In the picture below, a new leaf going in (left), and another which has been in the tank for 1-2 weeks of being browsed upon (right).