Macerator Pumps

Macerator pumps serve two purposes on your boat. They grind solids into a thinned out slurry and pump it away. They’re most commonly used to drain waste holding tanks and fish boxes. Think of a macerator pump as a wastewater pump with a grinding system for solids. 

The macerator pump is a rotary pump, similar to most bilge pumps. They consist of a motor, an impeller, and a switch. Unlike the impellers in bilge pumps that are a soft rubber or lightweight plastic, the impellers in bilge pumps are hard plastic and stainless steel. These stronger materials allow the pump to grind solids into a slurry for pumping out. Where you run the macerator from is personal preference. Some boat manufacturers place the switch in the cockpit, while others place it in the console. Some prefer to be within earshot of the pump as it runs to detect any issues. 

Macerator pumps are required in a few instances. For fishermen, they’re most often required to drain fish boxes. This is for a few reasons. Unlike other storage areas, which can drain into your bilge to be pumped out by your bilge pumps, draining your fish box into your bilge could lead to some awful smells and insect problems.

Additionally, normal bilge pumps aren’t built to stand up to the debris present in fish boxes, and would quickly fail. These pumps are perfect for the job, providing durable uphill pumping.

Live-aboard boats with large holding tanks also frequently use a macerator pump on their waste tanks. Similar to a fish box, your sewage tank is not something you want draining into your bilge. These pumps can turn toilet waste into a fine slurry to pump out of a sewage line at a disposal site or pump offshore when legal. 

There are a few things you need to avoid on your macerating pump. Although they are durable and meant to macerate small solids, they can break if abused. On fish box macerating pumps, avoid putting sinkers, swivels, hooks, and lures in or near the macerator pump drain. These items can jam even a stainless steel macerating pump and cause it to fail prematurely.

In the case of a holding tank macerating system, avoid putting paper towels in the system, and always be sure to use septic-safe toilet paper. Conventional toilet paper and paper towels can bind up the blades of a macerating pump. Try not to run your macerator pump dry for too long as it can cause harm if run dry for prolonged periods. Another way to improve your waste tank storage system is to use inline carbon vent filters. These filters help to reduce the amount of odor coming from your waste tanks.

Macerator pumps are a great fixture to have on your boat whether they’re used for pumping out waste tanks or fish boxes. With simple precautions, you can prolong your pump’s lifespan. When it is time to replace it or improve your system, Boat Outfitters has you covered on macerator pumps and accessories.

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