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How to Pump Out Boat Holding Tank at Home? – 5 Easy Steps

Fact checked by William Hart

how to pump out boat holding tank at home

Is it time to empty your boat holding tank but you can’t find a pump-out station nearby? No worries! The solution is simple – a macerator pump.

You will connect the macerator to the tank and two garden hoses. One garden hose leads the waste from your boat to a container or septic sewer. The other one pumps fresh water into your tank to rinse it. When you finish setting up, hold the switch in the on position and the tank will empty itself.

Waste tank pump out might seem yucky and scary at first, but it is simpler than you think. Leaks, messes, and odor are out of the picture with our step-by-step guide on how to pump out boat holding tank at home.

Table of Contents

What to Prepare

1. Two garden hoses

The hoses should be in different colors so you won’t mistake one for the other. For hygiene, only use these hoses for pumping out the boat holding tank.

2. One macerator pump

A macerator pump is a Y-shaped device. You must purchase macerators that are compatible with your boat. The device should come with two adapters and two electrical wires with alligator clips.

3. One 12-volt battery

Steps to Pump Out Boat Holding Tank at Home


Step 1: Prepare for the pump-out

Attach the adapters to the garden hoses and connect them to the macerator pump.

Remove the holding tank’s cap, attach the macerator pump to the tank through the hole fitting, and lock the device in place.

Then, connect the fresh water hose to the freshwater inlet and plug the discharging hose into the discharging outlet.

The waste will pump out under pressure, so make sure all the joints are firmly secured.

Finally, attach the alligator clips to the 12V battery for electrical supply. Pay attention to match the correct polarity.

Step 2: Pump-out process

You can put on a mask and a pair of rubber gloves if necessary.

When you are ready, hold the power switch in the on position to pump out the trash. It usually takes one to two minutes for a 15-gallon marine holding tank pump-out.

You should hear a distinctive sound when the macerator is free of liquid. Release the switch to stop the procedure.

Step 3: Rinse the holding tank (optional)

Open the fresh water valve to add water to the holding tank. Be careful not to overfill. Then, close the valve and switch on the macerator pump.

The device will draw the water out of the tank, thus rinsing it and removing residue. You can repeat this step several times to make sure the tank is clean and odor-free.

Step 4: Clean the macerator pump

Don’t store your pump when it still holds black water residue.

You can disconnect the power, unplug the hoses, and hold the device under running water to rinse it. Remember to wear disposable gloves.

If you don’t want to contact the black water. Follow these steps:

  • Step 1: Disconnect the device and the vessel.
  • Step 2: Reinsert the device’s cap and lock it in place.
  • Step 3: Open the freshwater valve and hold the switch at its on position so that clean water runs through and rinses the device.
  • Step 4: When it is clean, close the freshwater valve before releasing the power switch.
  • Step 5: Remove the device’s cap and hold the power switch one last time to flush out any remaining water.

Step 5: Finish up

Disconnect the alligator clips, unplug the garden hoses, and replace the holding tank cap.

You can find the instructions and visualize the whole process in this video:

Tips to Prevent Clogs When Removing Boat’s Waste


Clogs can make it difficult and messy to pump out the boat’s waste. Save our handy tips so they’ll never bother you.

1. Maintain your marine toilet properly

Toilets might become clogged after a time of use but you can always prevent it with white vinegar.

Once a month, pour two to three cups of vinegar through the head and give it a single pump every five minutes.

When the vinegar is out of the system, flush fresh water through the lines a few more times.

The acids in the vinegar will dissolve small clogs in the toilet and keep you away from trouble.

Also, only use marine cleaning products for your boat’s toilet, and avoid putting oils and fats in the waste tank.

2. Pump out regularly

A holding tank needs cleaning every one to three months, depending on its size and frequency of use.

Even when you don’t often use the boat’s toilet, you must pump out at least every three months to prevent clogs.

Before you winterize or store your boat for a long period, you should also empty the holding tank.

3. Invest in a high-quality macerator pump

Low-quality pumps can cause clogs, leaks, and even breaks in the middle of the procedure.

If you intend to live a boat life, you will have to empty the holding tank every other month. So, invest in a high-quality macerator pump.

Where Can I Pump My Boat’s Waste to

Sewage from vessels contains pathogens and can harm the environment. You must always dispose of the waste responsibly.

If you’re on land, find an appropriately-sized waste container or approved septic sewer system to pump out the boat toilet.

Don’t attempt to pump it directly into your household toilet and flush. The large volume of waste might clog your toilet and cause hygiene problems.

In the U.S, it is legal to dump waste in open water (at least three miles offshore). But only if your boat has a waste-treating device.

Improper sewage disposal might result in a $25,000 fine.


That’s how to pump out boat holding tank at home within five steps:

  • Step 1. Set up the macerator pump by connecting it to the tank, two garden hoses, and its power supply.
  • Step 2. Hold the switch at its on position to start the suction.
  • Step 3. Rinse the holding tank.
  • Step 4. Clean the macerator pump.
  • Step 5. Disconnect the pump with the tank, garden hoses, and power supply. You should let it dry and store it properly.

Once you get used to the procedure, you only need five minutes to carry it out.

Remember that clogs will happen if you make the holding tank store waste for too long. Grab a macerator pump and do it now.

If you encounter any problems, reach out to us via the contact page. We are more than glad to assist. See you then!

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