6 Steps to Help Prevent Aquarium Leaks

A level tank is key to aquarium leak prevention

A level tank is key to aquarium leak prevention

A thriving saltwater system is a thing of beauty and a joy to behold—as long as the salt water stays in the tank where it belongs, that is!

While most of the aquariums manufactured today represent a high level of craftsmanship and will provide the hobbyist with many years of reliable service, leaks—even full-blown floods—do occur from time to time. To this I can attest from personal experience!

So what can you do to minimize the risk of turning that costly Heriz rug into a wet sponge, harming your beautiful hardwood floors, or converting your fishroom to a wading pool? Follow these six steps to a leak-free saltwater aquarium:

Step 1: Handle your new tank with kid gloves

A leak-free aquarium starts with proper handling of the tank from the moment you purchase it. Whenever you’re carrying an aquarium, two sets of hands (or more) are better than one, so be sure to enlist someone’s help when bringing it home. At the very least, have another person on hand to open and hold doors for you.

Also, make sure the vehicle you’re using to transport the tank has adequate cargo space to accommodate it. Don’t assume it’ll fit nicely in the trunk. Measure the space ahead of time! Also, bring with you an assortment of blankets, foam sheets, or similar materials to provide cushioning and prevent the tank from cracking if it should happen to shift and impact something inside the vehicle while you’re driving.

Step 2: Perform a test fill-up

Next, place the tank (on its stand) in a location where dripping water will do no harm—such as outdoors or in a garage or basement with a floor drain—and fill it with tap water. Leave it filled for at least 24 hours, and then check the tank thoroughly for evidence of leaks at any of the seams. It’s a good idea to towel dry the outside of the tank after filling it so you won’t mistake spilled water that has pooled in the bottom trim for a leak. If you’re confident that the tank is leak-free, go ahead and drain it and move the tank and stand to their final destination in your home.

Step 3: Level the tank

But don’t refill that tank just yet! First, you’ll need to level the tank from front to back and side to side using a spirit level. If you need to use shims to get that bubble dead center, place them between the stand and floor—not between the tank and stand.

Step 4: Secure the rockwork

When positioning rockwork in the tank, it’s best to put down a thin layer of substrate material (assuming you’re using a substrate) to serve as a cushion between the rocks and bottom pane and then fill in with more substrate around this foundational rock layer until the desired depth is achieved. This will help create a stable rockwork base that cannot be easily undermined by digging or burrowing species. As an added layer of protection against live rock avalanches, it’s also helpful to secure the rocks in the pile to one another using plastic tie wraps (zip ties) or aquarium-safe epoxy.

Step 5: Protect against a sump overflow

If your system includes a sump, make sure it’s large enough to accommodate any water that might backflow from the display tank down through the return line in the event of a power outage or pump failure. It’s also a good idea to drill a small hole in the return line nozzle just above the water surface. This will break the siphon immediately if power or pumping action is lost, so the sump will need to accommodate only the water that remains in the return hose or pipe.

Step 6: Perform routine leak inspections

At least once a week, give your aquarium a close inspection to make sure there are no sneaky leaks. Run your fingers along all hoses, pipes, connections, clamps, and seams in the system to see if anything feels wet. Remember, little leaks can lead to big problems if they go undetected.

What’s your secret?
Okay, salties! I’m certain we’ve overlooked some good leak-prevention tips here. What’s your secret to a leak-free system?


If you enjoyed this post, subscribe to get our new posts in your email.
About Jeff Kurtz

Jeff Kurtz is the Co-founder/Editor of Saltwater Smarts, former Senior Consulting Editor for Tropical Fish Hobbyist Magazine, and the aquarist formerly known as “The Salt Creep.” He has been an aquarium hobbyist for over 30 years and is an avid scuba diver.


  1. Matt Bowers (Muttley000) says

    On step three I would add that the flatness of the surface is very important. If when setting the empty tank on the stand there is an air space anywhere between the tank and the stand, something is wrong. Some use a thin layer of foam to help smooth out small irregularities where the tank meets the stand. Also if a stand is set on carpet check regularly that the level didn’t change. Carpet doesn’t always compress from the weight evenly. Often along the wall there is other material under the carpet, and over time the tank will lean ever so slightly away from the wall. I always have a look during water changes. The top frame gives a good point of reference as the water level goes down.

    On item 4 I have used pieces of egg crate light diffuser under the rock work. Glass doesn’t do well when pressure is concentrated in a small point, so the egg crate helps spread out the weight, particularly before filling the tank. If a burrowing animal decides to remove sand around the base of a rock it helps keep the rock from shifting. It also keeps from scratching the bottom up when moving around larger pieces of rock.

  2. Very good tips, thanks for sharing.
    In my opinion the test fill is the most important.

  3. Paul Baldassano says

    Under my tank I built a slight barrier that will pool any leaking water there. I used aluminum angles that are used to hold up the edges of suspended ceiling tiles. In that area I built a leak detector that shuts off the pumps that feed the skimmer in the event of a leak. (I don’t have a sump but if I did, it would shut that pump off also)
    I just ran a wire from the neutral terminal of the GFCI that the pumps are plugged into along with a ground wire from the GFCI and taped them to the floor. If they get wet, they kill the GFCI shutting off the pumps. Is it legal to do it this way? I doubt it. But the neutral and ground carries no current so it won’t shock you. But I didn’t say it. (Master electrician 40 years) I also have this under my domestic hot water heater. If the thing leaks, the home made leak detector shuts off the power to an electric valve shutting off the water to the heater so my basement doesn’t flood.

    • The nuetral can carry current and will shock you if you are grounded as the nuetral carries the inbalance of the load and wants to find the easiest way to ground.

  4. One thing you forgot is to make sure you have a check valve installed on your return line.

Speak Your Mind