Where is the fine line between needed and redundant filtration?

[MultipleTankSyndrome]

Edit: nevermind, I probably don't need to make a thread about this. Answers ought to be available by search.
This can be deleted by the moderators if they so choose.

 

[duanes]

This is an important question, and I know you know the answer.
But it will also illicit many opinions, controversial, and benign, because there are so many filtration contraptions available, and we often see many questions about what is best.
But all filters do basically the same thing. Cheap ones, expensive ones etc etc
The bio part detoxifys ammonia and nitrite.
Mechanical filtration,pulls out aesthetically dis-pleasing stuff to the eye. Is this part needed? Maybe for most aquarists it is, but maybe not for the fish.
As long as filters control ammonia and nitrite, that's their most important real job.
Does tons of media make a filter better? Maybe, (but not really) the biological media will only contain a population that ebbs and falls with the tanks stocking levels.
If the aquarist over stocks, more media may be needed.
If the aquarist under stocks, there won't be more bacteria than the food the fish produce, so excess may be redundant.
If the tank doesn't have ammonia or nitrite spikes, the amount of media is adequate.
And...that media is just a space for bacteria to live on , it doesn't matter if its some expensive commercial doodads, or if its lava rock from a garden center,
It doesn't matter if its ceramic rings, or old used toothbrushes.

The most important part of 1st two types of filtration for me is cleaning out the crud.
If the filter is not cleaned, it fills with crud that changes from toxic ammonia and nitrite, to less toxic nitrate (notice the "less toxic" part).
The only reasonable way to get rid of nitrate, is with water changes.
You can have the largest, best rated filter in the world, but if its not regularly cleaned, and regular frequent water changes aren't done.....its a piece of junk, and slowly deteriorates the tanks water quality.
It may keep the water clear, but clear isn't always good or even important.
Unless the invisible toxins aren't removed, clarity ain't nothin.

One other thing, flow, and turnover does not equal filtration.
Some fish that come from swamps, and backwaters like bettas, and other fish that use atmospheric oxygen, may be fine with 2 turn overs per hour and be perfectly healthy.
Some rheophillic species like Tomocichla, or African Tigerfish, might need more than 10 Xs per hour just to maintain.

Above is my filter.
The bio-media is in about 6" on the left end.
There is a pad of Porette foam, for mechanical, that covers the @ 20 x 20 end of the 125 gal filter (sump/refugium) .

 

[esoxlucius]

Edit: nevermind, I probably don't need to make a thread about this. Answers ought to be available by search.
This can be deleted by the moderators if they so choose.

One of the most sensible questions you've ever asked on the forum, and you go and ask the mods to delete it! You're a funny cookie, lol.

 

[MultipleTankSyndrome]

Lol, I asked for this to be deleted because I had found what seemed to be the answer(s) in duanes' past comments, thereby making this thread redundant. But nothing was anything close to being like this answer, so it seems this is the answer instead and making this thread was worthwhile after all!

duanes' answer is a top tier one. Very explanatory and encompassing for newbies and experienced aquarists alike, thank you so much!
I didn't actually know the answer, so it ended up more helpful than they may have thought. All I knew was that a), filter manufacturer ratings are for a few guppies, tetras and angelfish, and so necessitate a degree of 'overfiltration' when dealing with larger fish and/or more fish, but b), this 'overfiltration' only needs to be sufficient to convert all the NH3 and NO2 into NO3, or else you're wasting your electric bill.
I did however know the importance of the filter cleaning from making an earlier thread about it.

Although I never directly processed that things like toothbrushes could be media, it makes sense considering nitrifying bacteria lives on decor, substrate, and suchlike. I also did know that all filtration serves the purpose of turning NH3 and NO2 to NO3 no matter how fancy it's marketed as.
My preferred media is plain old ordinary sponges. They are durable, have a lot of surface area for bacteria, are great for letting water flow through, catch a good amount of gunk, and easily release all that gunk during cleanings.

The overall takeaway I'm getting is that my planned filtration is probably sufficient, but not wasting my money. It was 264% the recommened filtration and 11.2x/hr tank turnover for a good amount of riverine/rheophilic fish (which the turnover at least falls reasonably well in line with what duanes guesses for riverine/rheophilic fish, even more so since there are a good amount of them).