A re-circulating flow-lane photo-incubator for benthicalgae experiments

摘要

Lab scale experimentation with benthic filamentous algae requires a microcosm able to provide control over the energy inputs necessary for growth including light, fluid flow and dissolved nutrients. Currently, there are few freely available and published designs for benthic algae incubators that illuminate the design rationale and details on incubator construction. From limited design details presented in a published article, the newly formed Auburn University Algae Lab reverse-engineered a flow lanephoto incubator in order to experiment with benthic algae growth on tile surfaces. The incubator consists of five geometrically identical flow lanes at 10 cm in width and 100 cm in length fed with a recirculating flow from a common reservoir. The flow lane assembly rests on a mobile aluminum T-slot frame that also allows for the fluid reservoir to be stored underneath the flow lane. Water from the reservoir is delivered to a manifold underneath the inlet side of the flow lane using a 22 LPM submerged pump before being distributed to a 2-18 LPM flow meter at the inlet of each flow lane. Water from the flow meter enters an inlet area where it is collimated to reduce turbulence and produce a smoother flow in the channel. Flow depth in the channel portionof the flow lane is controlled by a removable sharp edge weir at the outlet. Removable fluorescent full spectrum grow lamps rest on top of the incubator perpendicular to flow direction and are modified with slotted brackets to allow for adjustable heights above the flow lanes. The set of flow lanes under common lights allows for replicated experimentation on benthic algal colonization and growth under set conditions of volumetric flow rate and nutrient concentrations. Results from pilot growth experiments using a mixed community of attached algae showed that biomass characteristics did not significantly vary among the five flow lanes in the incubator.