FILTRATION AND UNDERSTANDING BACTERIA

After speaking to a friend of mine who told me he just cleaned his community tank out and now his fish were dieing. I asked what did you do he said i cleaned all the tank and gravel and replaced all the filter media with new. I explained that was the wrong thing to do and why. So i thought i would explain this in easy terms to anyone reading this blog who does'nt understand about filtration and bacteria in the fish tank. So this is how it works the fish in your tank even goldfish produce waist and amonia which is deadly to fish. So we add a filter internal or external they do the same job its not just there to filter debris and waist food produced by the fish. If left for a couple of weeks longer if you have the patiance a bacteria builds up that turns the amonia to nitrite. Nitrite's in high levels are also deadly to fish so another baceria builds up that turns the nitrite's to nitrates which are tolerated by fish if they don't reach to higher level. This is the main reason for water changes to dilute the nitrates. So if you decide to clean you tank never replace all the filter media just change some and leave some so the bacteria is still there to multiply. If your filter is filled with sponges then clean them gently in a bucket of tank water so you leave some bacteria on them to multipy again. This is also the reason we don't add fish to a new tank untill the filter has had time to build up the "GOOD" bactria. In the case of a discus set up the filter has to be even more mature because discus are more delicate than most tropical fish for discus about six weeks minimum longer is better. You can buy test kits for amonia, nitrite, & nitrates. So set up your new tank and watch the amonia and nitrites go through the roof after about a week you will see them slowly come down then dissapear once this has happened your tank has cycled and you can add fish but not to many at a time give the bacteria time to build up to cope with the fish waist slowly does it. keep an eye on the nitites and amonia levels they should always be zero. Hope this helps you to understand why you must have bacteria in the filter and why you should never completely clean a filter.