How much sunstrate should I use?

[fishkiller]

I have a 29 gal skimmerless with a little LR and shrooms and a couple damsels. I have about a half inch of crushed coral. I'm going to replace most of it w/ arragonite, but how much should i use??

 

[fishkiller]

OOPS, I meant suBstrate

 

[fishtails]

I'd say go with around a 3-5" agronite...Yes, please do remove the crushed coral because it will become problematic in the future....
Good luck....