Tridacnid clams come in a variety of colors, shapes, and sizes. Because of this, each species has their own set of requirments, and while most clams will thrive in just about any reef aquarium, it’s important to meet their specific needs so they thrive. Derasa, squamosa, and gigas clams all grow to be quite large and do best when placed in the sand with plenty of room to grow. Maxima and crocea clams are a bit different. They stay fairly small and live on hard substrates like live rock, where they can attach with byssal threads or erode the rock out a little bit to carve out a nice little place to sit. Clams placed on the wrong substrate may still do very well in your setup, but it’s ideal to get them in the right location in your aquarium from the start. This will promote the best possible situation for the clams to thrive.