Whether you’re just getting into fishkeeping or you’re ready to move up to a bigger tank, you’re bound to come across the idea of a sump when doing your research. But what is a sump and how does it work? More importantly, do you need one? Let’s find out.
What is a Sump?
Basically, a sump is a second tank that is set up under the first one, and the two are connected with tubing. The top tank is the display tank, meaning it holds all your beautiful fish and plants. The sump is something different.
Some people use a second glass of acrylic aquarium to set up their sump, but it can be something as simple as a large durable plastic storage container. Remember, no one is going to see the sump, so it doesn’t necessarily have to be pretty.
Because the sump is set up below the display tank, water naturally flows from the tank into the sump. Then, a pump sends the water from the sump back up into the aquarium.
Balancing this cycle is one of the big things about using a sump. You have to return the water to the tank at the same rate that water is draining into the sump or the sump or tank is likely to overflow, which, as you may imagine, makes quite a mess.
To help with this, sump setups also have an overflow. A good example of an overflow in your home is in your bathroom sink. Most have an overflow drain at the top of the rim of the sink bowl. If the water gets that high, the overflow allows it to drain out of the sink instead of spilling out onto the floor.
The overflow in a sump and aquarium setup works on the same principle. It can be internal or external, but an overflow typically sits at the top of the display aquarium, and water flows from the top of the tank, into the overflow, and down into the sump.
Another part of maintaining the balance of water flowing in and out of the sump is the return pump. The GPH of this pump in some ways determines the speed of the water circulating from the tank to the overflow to the pump.
As long as the pipes connecting the sump to the tank are large enough, setting up this system isn’t that tricky. To be on the safe side, some people only fill their sump halfway so there is room for excess water without risking overflow.
Why Use a Sump?
Now that we’ve covered the general setup, you might still be wondering what a sump does. The truth is, there are a lot of reasons to use a sump.
One of the main reasons to use a sump is that it makes your display aquarium much prettier. By placing your heater and filtration system in the sump instead of in the tank, the only things you see in the display tank and your plants, fish, and decor. No equipment eyesores.
Since the water is all circulating through the same system, it is filtered and heated in the sump, circulated through the tank, and then returns to the sump to go through the process again.
Another great reason to use a sump is that it increases the water volume of your tank. You’ve likely heard that larger tanks are easier to maintain than smaller ones. That’s because if you only have three of five or even ten gallons of water, there isn’t a lot of room for error.
The more water volume you have, the longer it takes for imbalances to occur. For example, say there’s a power failure and your pump is off for a day. In a small tank, this might be enough to make ammonia levels skyrocket. If you have a sump, though, it would take a lot longer for that to happen.
There are many other reasons to use a sump. You can add algae refugages to encourage algae to grow in the sump rather than in the main tank.
Tips For Setting up a Sump
Here are a few things to keep in mind when setting up a sump:
Make sure you place the return tubing as far away from the overflow as you can. If the return tubing is placed too close to the spot where the water drains into the sump, it means that the water in your tank isn’t cycling enough. You want to encourage good flow around the entire tank to ensure all of the water cycles through the system.
Leave at least enough space in the sump to hold the water contained in all of the tubing. If there is a power failure, gravity is going to pull all that water back into the sump. If there isn’t room for it, it will overflow.
Do I Need a Sump?
This question is something only you can answer. You don’t necessarily need a sump, but as you can see, there are a lot of reasons to use one. In the long run, using a sump may make it easier to care for your tank.