Tank Mates advise

[NewportRI]

New to this site, thanks. Fan for a long time!

I recently set up a 180 tall and I have two good sized stingrays (tea cup & hetrix), a 4-5 inch Australian Arrowna and a large blood parrot. What are some other good tank mates? The tank is 3 quarters sand and the other quarter is rocks and live plants.

Can I put a large cunch sea shell in the tank?

Thanks,

 

[53special]

Do you mean Conch? They are saltwater.

 

[NewportRI]

Conch is what I mean, typo.
The shell is big. Do not want to end up raising PH.
Thanks,

 

[Cichlaholics Anonymous]

the shell might affect the pH so I wouldn't add it