just a 50gal now days.I agree with @juniorrocketdad
I have a derasa growing out in my sump. The thing is bulletproof, it’s survived all manner of screwups. I’ll post a pic in 2 weeks when I get home. They are also pretty spectacular with colour.
What size tank do you have Steve?
Tell me, is you sump illuminated? Soryy, I have never kept clams, but believe they all need light?