I'm using pool filter sand and I noticed after adding a bunch of driftwood into my tank, my cichla were doing a lot better. Their markings are darker and they eat way more. They're not as skittish and come racing to the glass every time someone walks by. I siphon my sand every time i do a water change.
I noticed that too! My kelberi isn't as skittish anymore.
That's what I was thinking! What type of gravel did you use?