Dry rock questions

So my aunt outside her house has lots of natural garden meaning nothing has been sprayed on them um but a lot of it is dry base rock and coral we live in Miami so its normal amoike the same same rock at coral castle if u have ever been. What's the process of getting this in my tank? Has a lot of holes and stuff beautiful rock and there's so much that I could really do my tank up . Its been sitting in sun for years with just rain on it and what ever else falls from the sky. Some have a little dirt on the out side can wash it off. But can I just put it in my tank?

 

Going to do a 5 gallon change today so wash think maybe let it sit in old water for a couple days then drop it in the tank ans scape. Only have two fish but would prefer for them not to die or my coral in cycle. That I know will come but worth it if I can get all the rock I want in with out anything dying .

 

I'd be careful about taking rock like that. It could contain a lot of contaminants. You might want to run a test by setting up some salt water (using RO/DI) in a container with a powerhead running through it then test after a few weeks to see if any phosphate, iron, etc. has leeched from the rock into the water.

 

+1 on that I would let is run and test after a couple weeks