Review on 🐟 Lee's Original 15/20 Undergravel Filter: Superior 12-Inch by 24-Inch Filtration System by Julie Parker

Over the past twenty years or so I've heard a lot about not using underground (UG) filters, especially with plants. aquariums. I am very suspicious of this conversation. I've been using gravel packs since the 1960's and almost all of these tanks are planted. I didn't have a problem with any of these tanks except the first one and that was because these early filters only had 1/2 inch risers so had very low flow rates and deadly anaerobic bacteria could easily find unthreaded pockets to grow; grow. After the manufacturers switched to 1" risers the problem was solved. I've always had excellent plant growth in all of my tanks. I suspect the main source of these stories are people who have a vested interest in selling expensive canister filters and sump systems Undoubtedly, once configured and installed, these systems are truly of supreme value and essential for fish that constantly move the substrate and close the biological filtration of the UV filter.Goldfish and cichlids do very poorly in it.For the average hobbyist with little For fifty to two hundred dollar filters, however, there is a system here that works almost as well and costs a lot less.This system includes a simple hanging filter and a UG filter fitted with a power head.In my experience there are other than that UG filters no other biological filtration system My reason for believing this based on the time it takes to traverse a new system. When I hear very experienced people talk about canister and sump cycling, they almost always say it takes about a month for their tanks to cycle. Using UG filters and checking for ammonia and nitrites daily has never lasted more than a week. If I mix my gravel with a handful of gravel from a built in tank I can cut that down to two to three days. The big argument I hear against UG filters is the dirt that collects under the filter plates. It's ugly and smells bad. This dirt is a mixture of fish droppings, uneaten food and fallen plant leaves and is subject to a decomposition process caused by bacteria and fungi. Aquarists call it mulma. Gardeners have another name for the same when they find it. It's called compost. Gardeners collect trash (uneaten food), droppings (dung) and all manner of plant debris, collect them in huge piles and let them decompose for months, making them a great addition to any garden soil. The same thing happens with the UG filter. why is it good Dead leaves, fish food, and feces contain huge amounts of all the minerals needed for plant growth, and I mean everything, including micronutrients, unknown to scientists. But there is a problem. These minerals are in a form that plants cannot use. They are insoluble. Plants can only absorb nutrients that are dissolved in water. In order to convert these solid wastes into soluble plant foods, they must be broken down, and this is best done with the help of fungi and bacteria. In order to do this with a minimum of unpleasant odor, the decomposition must take place in an oxygen-rich environment. This condition exists in the gravel and under the UV filter plates. If there is an excess of decaying material, it can accumulate on top of the gravel. That's why we have gravel vacuums to remove the unsightly excess. The mulma under the plates is harmless. It will slowly but surely return to a soluble state where excess water can be removed with regular water changes. Another advantage of the UG filter is the exchange of oxygen and carbon dioxide. Most aquarists know that plants need carbon dioxide during the day to perform photosynthesis, and in high light conditions they can use up the carbon dioxide available, causing the water to become supersaturated with oxygen in a process called beading. What most people don't realize is that plant roots constantly produce large amounts of carbon dioxide and need oxygen for healthy growth. The UG filter pulls CO2-rich water out from under the roots and pushes oxygen-rich water through the gravel to nourish the roots. In summary, the UG filter promotes the decomposition of clay and circulates the resulting nutrients through the water column while CO2 and oxygen are evenly distributed throughout the water column. (NOTE: When using a UG filter, there is no difference between the substrate and the water column in terms of nutrients. The water column moves freely across the gravel bed, transporting nutrients to all parts of the tank, including the plant roots. As evidence, that you won't see dead brown roots with a UG filter, the roots are uniformly white.) Now let's talk specifically about the Lee filter. There are other UG filters out there and I'm sure they are very good, but personally I've been using Lee filters since the seventies and never saw a reason to look for another brand. They do their job and do it well. I would highly recommend them to anyone looking to use a UG filter in their aquarium.