Odd as it may seem to those of you who just have the one bowl boy and use suppression chemicals and water changes, some of us larger population aquariists like to keep a cyborg fish in our tank as well.
They're usually black, powered by an outlet and make noises like a hungry cat eating a cup of tuna.
These are powered filters. Most powered filters are also bio-filters.
Lets beat about the nitrification cycle... Nitrosomona and Nitrospira eat ammonia and nitrite and air
. Some of this air comes from air and some comes from the water molecules themselves. Both Somo and Spira have to poop and they must have clean water to do so, loose but accurate you may consider clean water as "fiber" for anything that lives in water.
Fiberous mats, sponges, layers of rock, silk plants in shade, ceramic rings, bio balls, bio wheels, bottom sand and so on. Both Somo and Spira like these environments, they're creatures of shade and secrecy.
So your cyborg fish, the power filter, grows them on the inside - not just on the material designed for it - on all surfaces, around the impeller, inside the bubbly pipe, inside the intake tube. Everywhere there is shade and flow of any kind you will get nitrate pooping bacteria. It will grow them on the carbon in the cartridge or bag or basket, it will grow them where water splashes on the lid. It will even grow them between the rare earth magnet and stainless spindle of the impeller assembly.
But the only place you WANT these to grow is in the bio-media. You want a strong thriving community in that bit alone so that your cyborg doesn't get gummed up inside and start to fail its collective.
No matter what the bio-media is it is going to give off hydrogen, so expect fishy smell.
The care of your cyborg is easy. All of them are made with removeable bio-media of some sort or another. As often as every time you change the filter or at least twice a year your little power friend needs cleaned out.
Do a water change to a bucket and toss the bio-media in there.
Take Mr Fusion to the sink and turn him upside down then spray straight hot tap water up his insides at an angle (no dribble on sprayer!) until he's nice and warm, then disassemble him carefully. Run more straight hot water over all the bits and pieces and up inside his nooks and crannies. Get out the brush and gently run it through every surface, every pipe, along ridges and into nooks. Good manufacturers include a brush for cleaning the tiny bits but if you need a brush you can usually use a twisted bundle of pipe cleaners.
Things to check that are important on your sci-fi fish.
Impeller shaft spin. Does the impeller spin very freely on the shaft AND rock up and down the shaft just a little? Vineagar then thick salt water and rinse.
Impeller socket crust. Is there any hard water deposit inside this? Vineagar!
Intake pipe connections. Are they loose? Teflon tape used like an ace bandage between the surfaces!
Dry the tin fish carefully, you won't get all the water off but the use of hot water to clean and about 10 minutes dry time will remove "all" the chlorine, there will be water conditioner.
Assemble Iron Fish carefully and diligently. If you need lubrication on parts for assembly use a drop or two of WATER CONDITIONER on the contacting surfaces. Once he's back in one piece give him a little cuddly shake then add about a gallon's worth of water conditioner to his little nose and slap him back where he goes for the next two to six months. New carbon filter, put in the new treated tank water through him and power him up.
Vroom! Happy cyber-fish.
Knocking sounds after the water flow establishes are usually bad assembly and you need to pull bits apart. Expect occasional bubbles and give him about an hour before you put the bio-media back in.
Some antibiotics that save your fish can kill your bio filtration, its usually best to go to manual water change care when doing ANY antibiotic, mineral, salt, natural extract or chemical treatments. Your bio media can sleep dry for up to six months if it is not exposed to light, sterilizing chemicals or ozone. I constantly rotate my backup filters across the tank for two days a week so I've got something that will work in an emergency for myself or my local aquariist friends.
So remember, if you have a powered filter you must consider ITS health too!