 Trace metals, like iron and manganese, are essential for ocean productivity, but what controls trace metal concentrations in the water column? The answer is complex and controlled by a variety of factors, including ocean circulation, atmospheric deposition, and, importantly, biological uptake and regeneration. In this paper, we use controlled laboratory experiments to explore the role of decaying phytoplankton in the cycling of dissolved trace metals and macronutrients in the ocean. Phytoplankton take up trace metals and macronutrients in the euphotic zone and release them after they die as they decay, through a process known as regeneration. To simulate this process, we conducted controlled laboratory incubations using Gulf of Mexico phytoplankton communities. We incubated three mixed phytoplankton assemblages, as well as monocultures of the diatom pseudonychia de la rosa and the dinoflagellate carinia breves. In each case, the phytoplankton groups were allowed to first grow, then put in the dark to decay. Over a period of six months, the incubations were sampled at regular intervals for the concentrations of trace metals and macronutrients, as well as for chlorophyll A, particulate organic matter, scanning electron microscopy, bacterial counts, and 16S RNA gene analysis. The study allowed us to isolate the process of regeneration with respect to time and compare it to ocean depth profiles. We found that while some metals, such as cadmium, tracked closely with the macronutrient phosphate, others, such as iron, lead, and manganese, were more governed by particle scavenging. Iron in particular showed a close relationship with manganese, regenerating only after manganese was depleted. In addition, we observed a close coupling of solistic acid and phosphate, which are generally decoupled in water column profiles. Although these experiments couldn't replicate the exact conditions of the ocean water column, they provide valuable insight into the role of regeneration in trace metal and macronutrient cycling.