Hello! My fiancé's father just gifted us two pieces of Texas Holey Rock that he says used to live in an eel tank. We have a 5g betta tank and a 20gl tank with about 7 danios, 10 harlequin rasboras, and a growing number of panda cories (they won't stop breeding!). The betta tank has mostly silk plants and a java fern in it, the community tank has driftwood and lots of natural plants. Both tanks are happy and healthy and parameters are perfect. After a quick google search, I'm thinking adding the rock might not be a good idea for either tank. Does anyone have any personal experience with this? Thanks!