After doing my high light co2 added tank with some of the pinks reds and even maroons, I wanted more color in the lower low and moderate light tanks. My solution was the stone and gravel yard and river rounds which come in several natural colors. Also lava rock will add red/
Sorry I have no pics with the blue hue, so I grabbed one off of the net:
Sorry I have no pics with the blue hue, so I grabbed one off of the net: