Are These Alright??

To test the rocks drop some vinegar on them. If it fizzes they are no good. If there isany rust on them also toss them. Another test you can do will make sure of it 100%. Take a bucket of tap water and use de chlor. Test the pH of that, and add the rock. Wait 24 hours and test again, If it changed a lot its also no good.

I cant tell what kind of sand that it. Is it play sand? Pool sand?

wait, if he's doing a cichlid tank isn't it possible that rock that raises pH is a good thing? I have a piece of tx holey rock that I used to have in my tank.I didn't know what it was but the pH in my tank stayed so high. I got wise to it and took it out. Later I saw some on e-bay and it's supposed to up your pH. People sell it for cichlid tanks.

Rocks should be fine, just scub them and be sure they are clean. Sand should be OK, But be sure there is nothing added in there for mixing cement.

The rocks won't dramatically change your pH any how most of the time. From what I can tell the ones you have there are fine. If your doing weekly water changes you probably won't even notice a change in the pH from the rocks. The sand I would be doing some checking on, it could change the pH easy enough, if it doesn't then its fine.

As to who said that if they are doing cichlids then a high pH is fine, well there are 100s of different types of cichlids, not all are from the african rift lakes. If they are infact from Malawi, Tangyanika or Victoria yes a high pH is good, if they are Uaru its not. Using a blanket statement like "cichlids" and assuming that they are all the same is inncorrect. The conditions a Discus or Angel needs is completely different from that of a Peacock or Frontosa.