Two Little Fishies' product line includes trace element supplements, calcium supplements, underwater epoxies, granular iron-based Phosphate adsorption media, and granular activated carbons.Independent studies show that some trace elements accumulate in home aquariums to potentially toxic levels. SeaElements avoids contributing to this problem by including only those elements that are typically depleted from aquarium water — in the proper concentrations and ratios. Other supplements promote a long list of elements in an attempt to offer something "more." We offer the only formula that contains just what your aquarium needs. 250 ml (8oz) bottle.