Under-Gravel Aquarium Filters?

[Wheely34]

Hi. I'm new to the forum. I will be starting up a new aquarium and wanted to know about under-gravel filters.

Currently, I have a 30 gallon tank. I just have the tank and need to still purchase a lid, light(s), heater, filter, gravel, etc. So, given that it is a 30 gallon tank, how would an under-gravel filter (rated for 30 gal.) compare to a normal top-of-the-tank filter? I was planning on purchasing the Aqueon Quiet Flow 30 Power Filter, but then saw this under-gravel filters and they struck up some interest.

Do these type up filters perform adequately? Will it perform the same as the top-mounted filter I originally was planning on getting? As for some additional information, after the tank is completely cycled and ready to go, I plan to have gravel, some live plants, driftwood, and a couple of fake plants also in the tank. As for fish, I have my mind set on 1 Rainbow Shark. As for other fish, so far I'd be purchasing a school of danios or some other type of fish that the Rainbow Shark "are known" to get a long with.

Anyway, that is the gist of what my setup will be. I've really taken interest in the under-gravel filters, but just wanted to make sure they are just as sufficient as top-mounted filters, or if there are any other known problems or annoyances (such as cleaning, etc.) with them.

Thanks.

 

[drobbyb]

There's nothing wrong with undergravel filters. They perform the job just as well now as when they were invented. Plans and undergravel filters will not mix however if you plan to grow your plants in the gravel. As the plan's roots grow, they will clog up the little holes in your undergravel filter reducing it's effectiveness. Also, periodically you have to remove everything from the tank to clean under the undergravel filter so that the water flow remains unhindered.

Pros:
Easy to use
Cheap

Cons:
Dated technology, newer designs can be more efficient
Major overhaul maintenance
Cannot grow rooted plants
Limited media choice
Limited stocking levels

There's something to be said about efficiency here too. You can increase the efficiency of an undergravel filter by replacing the air pump with powerheads, and this makes possible reverse flow filtration. This supplies a direct current of highly oxygenated nutrient rich water directly to the bacteria and also helps to keep the flow of water clear. This method is best when used in conjunction with additional filtration to pick up all the particulate matter that reverse flow kicks up. This additional filtration can be in the form of a prefilter for the powerheads, a HOB type filter, high flow box filter, etc. You get the idea.


Newer designed filters have the potential to be more efficient, but this does not make undergravel filters useless. You just need to know their limitations.

 

[KittyKat]

Under-gravel filters are more pain than they are worth and restrict the types of substrate you can use. There are plenty of things going against them and few going for. Compared to a good internal filter, the air pumps are noisy, decor can create dead spots, they need to be vacuumed regularly, not always suitable for plants, more difficult to remove the crud in one go.

Basically, a good internal or external filter well out-competes an under-gravel from every point of view for me..

 

[Wheely34]

Well I didn't even think of the plant growth being restricted. Cleaning would probably become an issue too. Thanks for the replies. Appreciate it.