Information about undergravel filters?

Question

Tank info.
55 gallon tank
already has filter with carbon cartridges
Questions
What do I need for this type of filter
Are they easy to use
Are they expensive

Answer 1

Undergravel filters are one of the cheapest and easiest to use on the market. If you ave the filter plates, lift tubes and carbon cartridges all you still need is an air pump, a gang valve and tubing. Air lifts water from the bottom of the tube up and out of the top causing the water to flow down into the gravel, through the plates and back up the tube. It's the gravel that's actually the filter in this case.

A better over all scenario though is to use reverse able power heads, one on each lift tube to blow water down the tubes, across the bottom of the tank and up through the gravel. This will provide the same biological filtration without trapping too much waste in the gravel bed or under the filter plates.

MM

Answer 2

Ah, the old undergravel filter question.

Basically for most aquarists, undergravel filters cause more problems than they solve. This is due to the collection of mulm (undecomposed fish wastes and other solid matter that accumulates in the aquarium as a fine, brownish, fluffy material) underneath the filter plate. Human perception, out-of-sight = out-of-mind, plays a part as well. A third problem is that water moves through the gravel, so the gravel MUST be evenly spread. Water flow channelizes along the path of least resistance, so water will flow more rapidly through shallow layers/holes giving less and less filtration over time.

Almost all filtration in an aquarium occurs because two types of bacteria live in the filter. One bacterial type converts ammonia to nitrite anaerobically (without oxygen); the second type converts nitrite to nitrate aerobically (with oxygen). All filter media provide two functions: 1) particulate filtration (mulm collection), and 2) a substrate for the bacteria to reside upon. Mulm removal occurs only upon rinsing the filter material; nitrate removal by water changes. if mulm is not removed, it will build up to a critical point, a point at which the tank crashes “becomes sour”. When this occurs, the oxygen level drops towards zero, and the water becomes acidic. As this crash can occur within hours, it is the lack of oxygen that kills the fish

In the case of undergravel filters, mulm collects in two places; 1) on and in the gravel, and 2) underneath the undergravel filter plate. Mulm collecting in or on the gravel can be removed via periodic siphoning. Mulm underneath the filter plate cannot be easily removed, and in most cases isn’t ever removed. Eventually the tank crashes!

Regarding use and cost, if you factor in maintenance costs/requirements as well as filter costs/requirements, they are very costly, and very difficult to use.

FYI: Undergravel filters were introduced into the aquarium hobby in the late 1950s. Sour tank syndrome started to appear in the aquarium literature in early 1960’s.

Answer 3

I personally don't think under gravel do anything. the waste still get in between the pebbles. Just get a canister filter. They are way much better.

Answer 4

try an internet search

Answer 5

sry i never had 1 b4 i think they r silent.