This stainless steel rack holds one to three Imhoff cones. It works exceptionally well when positioned near a heat source - a 100 Watt incandescent bulb - or in a well-lit, warm environment. Aeration is supplied to the cones by use of an external aerator. Flexible air tubing connected to an 18" length of plastic rigid tubing (Both items available at Brine Shrimp Direct) is an elegant, yet simple solution for directing air to the bottom of the cone. Directing air to the bottom of the cone keeps the cysts in suspension and effectively eliminates dead spots where cysts might settle. The rigid tubing also eliminates the need for clips or attachments. We've found that the best way to harvest the baby brine shrimp at the end of the incubation period is to remove the air tubing, allow the brine shrimp to slowly settle to the bottom and, using a separate length of flexible air tubing, periodically and gently siphon the brine shrimp out of the cone into an intermediate container. Care must be taken that the baby brine shrimp do not become too densely packed at the apex of the cone and suffocate. Harvesting brine shrimp in this manner, as opposed to using a cone or apparatus wherein the shrimp are drained directly from the bottom allows one to better control and to minimize the amount of unhatched egg or empty shell that is transferred into the intermediate container and subsequently into your aquarium.  Does not include cones.  Cones are sold separately and are shown only to illustrate use of the rack.