Is ash wood safe for aquariums? And if it is, do I need to dry it or do anything special to it?

Due to an emerald ash borer infestation my husband had to cut down two beautiful but nearly dead trees. Some of the branches are pretty neat. I know I'd have to remove the bark and scrape the outer layer that any borer larvae might have infested, but it'd be worth the work if it could be used the tank.

Too sad about the trees. They take so long to get there and then they have to go.
Some things to know about wood in general are common to all types of wood. If they are just cut, they are likely to still have lots of sap which to me almost always means they will color the water. Sometimes for a really long time. One way to tell how green or dry wood might be is by looking at the end of a cut piece. If it is truly dry, it will have little color change from the surface to the interior. Wood that has been cut this year often needs to cure for a year or more to burn well. This is because of the sap. I like wood in my tanks to be even drier to avoid color. If it is still holding bark, it would not be dry enough for me to use due to the work involved. Others might use it but I like to let nature do the work rather than me doing that much water changing.

Good info, PlantedRich! Thanks!

Are there types of wood that don't work in tanks? For example, I have some aged walnut, ash and oak in the basement from previous year trims that DH and I kept for woodworking or craft use. Assuming they're dry enough and I soak/rinse till the color leaching is acceptable, are those woods good for the tank or am I going to end up with a mess in short order?

Once fully dry, I find little difference in wood. Some take longer to dry and if there is sap and color, some like walnut seem to be much darker but none of it hurts the fish, only what we think of the tank. I'm told that cedar may have oils but I've never used cedar that is not fully dried so I can't say for sure. The dry I'm talking about is like wood that has been used as a yard ornament for years so that it is barely identified as cedar.

The only wood type I avoid (if dry) is something that is kind of soft and full of mushy stuff. I can't think of a type right now but things that I can squeeze? It just feels like it would not last and be a pain to pick the pieces out if it fell apart. I also avoid using anything with bark because when it does come off, it tends to blow around and I can never get it all collected. Just kind of a personal bug with me?

Thanks again, PlantedRich! Totally understand what you mean about mushy wood. And now I think I'm going to have some fun experimenting with the old wood in the basement. Gotta go find a plastic tub to soak them in and see which leaches. :-)

Oak and Walnut wood are tank safe. Any hardwood tree is okay. I have used water birch in my tank with no problem. I also have grape wood in one. It is trimmed from old grape vines.

Absolutely, you can use ash, if properly dried and cured. Ash is the wood of choice that major league baseball player use to hit 500 foot bombs. I'm sure it will be fine in your fish tank.