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Too much bio filtration?

Jan 4, 2006
I just discovered the AAOM (Advanced Aquarist's Online Magazine) and really liked what I saw -www.advancedaquarist.com. (I found it through researching Righty's info.)

I was reading through some articles on new tank setup mistakes and saw all the usuals, "overstocking", "no GFCI", etc. etc. But one thing I saw baffled me -"Too much bio filtration" was mentioned a couple of times.

I was of the belief that there was never such a thing. :confused:

You can have too little nitrate removal or too few water changes. Is this the whole "wet/drys are nitrate factories" thing?

Doesn't everyone want every bit of ammonia converted?

Isn't the final stage nitrate? and eventually, possibly nitrogen?

I have been out of reef keeping for a while - has something changed?
I've heard that too much bio filtration is a problem because the bacteria consume all of the nitrogenous compounds, multiply, and then there aren't enough nutrients for all the bacteria to survive. Mass die offs of these bacteria can cause a two fold problem: a) an increase in nitrogenous compounds and b) not enough critters to handle the increase in N-compounds. Granted, I think this condition is still pretty rare, but thats what I've heard/read.

In some reef tanks, it can cause a bit of a crash if you go away for a few days or something, and no new food items are introduced...in a ceph tank? No, you need as much filtration as is possible.

A die off from starvation is not normally a problem. A filter sort of consumes itself. This can result in more nitrates being released as bacteria die and rot but it's usually very gradual with die offs fueling regrowth. Bacteria also does not usually build up above levels that are above the available nutrients. New colonys may grow over old colonys resulting in a build up of mulm that may leech nitrates into the water but a little clean in tank water (not in the tank.... use a bucket) every now and again solves that problem.
The worst possible time to have to much bio-filtration is when the power goes out and all the snail ridden cannister filters sponges and bio media you haven't checked for a while bake in the summer heat with no O2 and thousands of tiny rotting snails for company. Then when the power comes on 6 hours later all the snail shells which have filled with gas and floated to the top of the impellor housing choke the impellors and stop them from priming and starting the filter. 6 hours later you rock up to the tank. Powerheads are doing great so lots of O2 and everyones happy. Rest of the tanks are ok. Woa, scary black out. Phew. Better check the cannisters and waterfalls though. As you walk up to tank see one cannister start spewing white cloudy water into tank as 1 impellor finally works its way free and spews into tank.
Watch all fish go to the surface with in 5 minutes as ammonia level skyrockets. Panic pull apart and clean stinkyest 2 cannister filters ever and perform 2X 50% water changes. Day saved and no deaths.
If you build it a home, and swish high O2 nutrient rich water thru that home you get bacteria. Take away the O2 and you get a big die off.

Sorry for ramble.... had to dig deep to think of a time when too much bio filtration had ever hurt.

Some reef people have other organisms that compete for the same things as the filter media beastys. Be they algae, sponges, corals, or what ever it is that lives inside liverock or at the bottem of the sand in ya tank. When it is all about balance you may want to help the live rock out by reducing competition from other bio media for available nutrients. Not something that is gonna stop me maxxing out my tanks with bio-filtration as I usually have plenty of nutrients to go round and keep the system stable with water changes. I clean some of my sponges reguarly to encourage species that are quick to recolonise to dominate. Others I let go to let whatever it is that lives in that gunk thrive. I like looking at filter water under a scope but crap knows what these weird things are or are doing most of the time. So many types....
and they are all eating each other or waving with a hundred hairy arms. Actually seeing these guys kinda complicates the whole nitrate cycle in my head. It's a jungle in there... and the best jungles have heaps of different species all living together. I often swap a handfull of the grit/sand or whatever from the bottem of my tank with a handful from another. These are trusted healthy tanks here and although it may not be the most scientific way to do it, 10 or so handfuls from different established reef tanks can really kickstart a new tank. :yinyang: get in as many different species as possible and the ones that are best suited to your tank will do well and reach a ballance.
To think I typed all that with a freshly smashed finger too!
Nail has gone black, hope the stupuid throbbing nail doesn't fall off.
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