Undergravel Filterplate Filter
Undergravel Filterplate Filter
The undergravel filterplate filter is a great choice for you if you don’t know how deeply you want to get into saltwater aquariums. It operates on a simple principle and there are very few parts. You can even make one yourself from readily available parts. But the downside is that it can’t filter larger tanks with lots of fish.
Undergravel Filterplate
There’s a small plate buried by substrate. In the corner, there’s a tube that draws water up by blowing bubbles. As the water rises in this tube, water from the tank is drawn through the substrate to the undergravel filterplate.
Because of bacteria that lives in the substrate, this filtration system constantly draws water through the bacteria so it can process toxins in the water like ammonia, nitrite, and nitrate.
Flow rate is determine by the number of tubes you have and the power of the pump that generate the bubbles.
This type of filter will be your least expensive and most beginner aquarium owners use this. If all you want to do is keep a few hardy fish like damsel fish and not upgrade, then an undergravel filterplate filter is a great choice.
Undergravel Filterplate Limitations
An undergravel filterplate filter, by itself, isn’t suitable for every type of saltwater aquarium (as you probably guessed).
The primary limitation is that it can’t handle a lot of fish. The undergravel filter’s effectiveness will always be limited by the amount of surface area you have in your tank. So if you add more fish, you can’t make the undergravel filterplate any more effective.
In other words, you really don’t have much of an upgrade path. The only thing you can do is add more tubes and airstones. However, because they’re limited by the surface area, they increasingly become less effective as you add more.
You have to carefully control the number of fish you add to the tank or you run the risk of maxing out your filtration system (and your fish dying). A good rule of thumb is 1 inch of fish per 5 gallons.
Another limitation is the oxygen. Bacteria use up a lot of oxygen quickly and they can quickly strip the water of all the oxygen. Ideally, you should have 7-8 ppm of oxygen dissolved in the water.
The primary way oxygen enters your saltwater tank is through aeration between the air and your aquarium water surface. The bubbles in contact with the water help introduce some oxygen into your saltwater aquarium but not much.
The greater the load is in your tank, bacteria strip more oxygen from your water, leaving less for your fish.
Undergravel Filterplate Maintenance
Although this is a really simple setup, it still requires some maintenance.
Because salt will clog up airstones that produce the bubbles, you have to observe the quality of bubbles and change the airstone periodically.
Along the same lines, the tubes will eventually clog with salt residue. You will need to either clean or replace the tubing when this happens.