Just curious if there are any rocks that are toxic in the aquarium. I live on a very rocky hill and find some beautiful colored rocks at times. They would clash with my tanks but if I could clean them up maybe sell. Second question is what sort of paints are safe? Third I know it's a broad topic but what are known safe woods here in united states. I live in the PNW so my area has Doug fir,western Cedar,and various pines mostly. However for the moment I have some cherry and magnolia wood along with apple and pear later this year(trimming trees) .