Turtle related questions! Turtle people help please!

[Shelled TT Lover]

Do turtles sneeze?
I saw one of mine did sneeze today, under water, exactly like human do!
I have read the syndromes of pneumonia, but sneezing under water seems not included.
Do you see them do that? Very occasionally?

There is one kind of wood that can sit in water because of its very high density, and it can do something to lower water PH, what is its name? Is it good to let my turtles have them? I mean let my turtles live in low PH water.

Do you use substrates? I have nitrifiers in my canister filter so I don’t need to change my water very often. If I want use substrates to further enhance my biological filtration system, what kind of sub should I use?

3 questions! Please help!

[Shelled TT Lover]

turtle man show up!!!

[Graham]

I've seen mine "sneeze" underwater and I don't think it's anything to be concerned about, less so than if they did it out of the water anyway, I'm not sure what the reason for it is though.

I think you probably mean Bogwood, pH isn't really relevant to most species of turts as long as it's not too extreme, I think it's more important with softies than crusties.

The only substrate I use is a single layer of large (45mm) slate chips, anything else traps too much dirt, you could try some Alfagrog I suppose but I wouldn't have it too thick.

[Shelled TT Lover]

thanks Graham!
i have all the answers i need now!
i known you are good!
cheers my man!