I about to clean my tank and was going to rearrange a few things since my bichir just died (got out somehow), and theres no need for his safe cave anymore. Ive got a 120g freshwater tank, with a few large rock and driftwood, but wanted to add a few more rocks. I used to have a couple reef tanks and have some big base rocks sitting around (out for about 2 years), which used to be live rock at one time. Its not fugi rock or anything, more greyish in color, so it would look natural in my freshwater tank. If I rinsed these off fairly well, do you think I could use these in my freshwater tank, without effecting the PH to dramatically?