Mature Filter Media

[reflex1]

Could someone please explain what this is and what/how it works - TIA!

 

[OldMan47]

Welcome to the forum Reflex1.
It is an easy concept. Media is any of the sponges, filter pads and similar items that are in the filter and have water passing over or through them. A new filter is nothing but a piece of hardware that may some day become a biological filter. When fish use their gills, they absorb oxygen but they put out two chemicals, CO2 and ammonia. The CO2 is a gas and readily leaves the water. The ammonia becomes a compound called ammonium and stays in the water. Bacteria exist that remove the ammonia and replace it with nitrites and other bacteria exist that remove nitrites and produce nitrates. It turns out that ammonia and nitrites are poisonous to fish in very small amounts but that the fish can tolerate rather high concentrations, by comparison, of nitrates. Where that puts us with a new tank is that we need to grow those bacteria in our filters to mature them. Once a filter is mature, it can be used to start a new filter and give the new filter a huge head start. Up to a third of the media can be removed from a mature filter and replaced with new media. That sample from the mature filter then goes into the new filter so that it starts out with a sample of the right bacteria in it. All that needs to be done after that is to make the filter's bacterial population grow to become a fully functional filter. We do that growth either by using a fishless or a fish-in cycle. I have a link to each type in my signature area.