Dead base reef rock ok to use?

[jefferzbooboo]

I'm planning on keeping a pair of electric blue Jack Dempseys in a 55g. I'm setting up the tank and have about 30lbs of Marco Rocks left over from a SW build.
Can I use these rocks or will they raise the pH to much?
I'm using Ocean Direct Caribean Oolite sand.

 

[roydesilva]

I'm planning on keeping a pair of electric blue Jack Dempseys in a 55g. I'm setting up the tank and have about 30lbs of Marco Rocks left over from a SW build.
Can I use these rocks or will they raise the pH to much?
I'm using Ocean Direct Caribean Oolite sand.

I have it in my african tank I no it isn't really the same as a American but it works great and it doesn't raise my ph