Too Much Filtration

[Ralph]

This question has come up in a couple different threads and I wanted to get some feedback. Can you have too much filtration and if so, is that a problem?
My thoughts on this are that the total number of nitrifying bacteria is limited by the amount of ammonia in the system. In other words, if you had 15 filters on a 100 gal tank, you would have the same amount of bacteria as you would with one adequately sized filter. Because ammonia serves as the nutrient for the bacteria, only enough bacteria could exist to "consume" the amount of ammonia that is typically in the tank. It wouldn't matter how many square inches of sponge you were using.
Is 15 filters a problem? The only drawbacks I could think of would be the cost of the extra filters, both initial cost and maintenance cost. Also the extra water aggitation would strip the water of CO2, a concern for planted tanks.
Does this sound plausible, am I missing something? I hope that this isn't too theoretical

[Carol_Roberts]

You bring up some good points. I want to have enough bioilogical filtration and water movement without wasting electricy and having a bunch of extra filters to clean.

For grow outs I like one aqua clear 500 on 55+ gallon, two AC 500's on 100+ gallons. A big sponge filter is enough for a 29 gallon with a pair.

Carol :heart1:

[BlueTurquoise]

I would have to say one possible drawback that I have noticed with over filtering is that there is alot of biological mass that is present in the water. ie. becuase there is a large surface for them to grow on they will thrive. I am not sure whether the limited ammonia vs size of population can be worked out in that way. My thought was always if you give them room to grow they will grow! limited food or not!

The water in a over filtered tank begins to smell quite a fair bit idicating massive bacterial growth inside the filters. I am not sure how good this is for the fish. I would say that alittle over adequate filtration is the best solution...jmo

Chong

Ralph....

I agree with you 100%. The biological capacity in any given filtration system is only large enough to consume the waste produced at that given time.
X amount of ammonia and nitrites will only support X amount of bacteria.
Consider what would happen if you FULLY cycled a tank with 6 guppies......then suddenly exchanged the guppies with 6 discus.....the ammonia and nitrites go through the roof untill the nitrosomonas, nitrobacters, etc. can increase in population enough to consume the extra waste produced.

As for extra water current....Ive never been one to believe that discus dont like current...mine actually "play" in it when Im refilling the tanks with a 900/gph pump! as long as they have somewhere they can rest if they choose....they like it. I think some current is good for them to an extent. a few possible exceptions I can think of is if someone were dealing with a male who was a weak spawner. They might want to avoid any serious water movement in that case, or a sick discus in a Q tank....or a pair with very young fry on thier backs.

Tony

[jim_shedden]

Carol : Your note is interesting. I have a 90 gallon with an Aquaclear 500 and two sponge filters. I was wondering what your thoughts would be of taking the sponge filters out and adding an Aquaclear 300 (because I have an extra one..... :)). I also feel that my discus enjoy some of the current. I see them sititng in the middle of it quite often.

Jim

[joanr]

Hi Jim,

I'm one month now without the hideous sponge filters in my community tank. I noticed that even cleaning them every 2 weeks, and that's rinsing to maintain bio effectiveness, never got them clean enough to rid them of the denizens of the deep, you know, those tiny little critters that jump or cling to the glass but don't hurt the fish? Got rid of the sponges, got rid of the bugs. That simple. I do run the AC's with pre-filters which get washed every night (the pre-filters) and that seems to be enough. My fish look healthier and happier with more room in the tanks and nothing to run into. My 125 has three 500's and a full time micron HOT going. It sparkles.

I know, this is controversial but it works better for me without the darn things. For breeder tanks, it might be necessary but I think a mini or 150 AC with a real thick pre-filter might not throw too much current or draw new free swimmers in. Don't know yet, haven't tried it as yet.

Joan

Tony, IMO, having alot of current in a tank expends energy which in turn will require more food intake. The fish will not develop as large and robust if the caloric intake is used up with just everyday activity. IMO, the discus will dash to the water change. It is fresh water replacing funky water! Also it is the oxygenation occuring because of the turbulance. I doubt they would enjoy being knocked around all day.

In the Amazon, the discus have the propensity to stay in the slow moving quiet inlets and not out where the plecos enjoy the swifter currents. Joe ;)

Joe,

I understand what you're saying about the natural habitat that Discus are found. But I think in the DAAH thread that Oliver added to there was a type of Discus that came from faster moving waters and they tended to be a thicker, stronger fish. I don't know about their overall size. But it makes sense to me that additional current will cause a fish to eat more, but we are all overfeeding our fish to begin with. Or at least feeding them as much as they eat so if the current caused them to demand more food they'd certainly get it. And additional current should lead to a healthy, strong fish the way it does in humans. Makes sense to me at least. I have the current from a Magnum HOT or 350 in addition to a sponge filter or two in most of my tanks. While the filter adds more current to the tank there are still dead spots and the fish can seek those out if they choose to.

Dave

Dave, I knew without a doubt that you would understand where I was going with this! Thanks for the info. I was unaware of the White Water Discus! Easy!!!JK JK!!

I regularly abhor analogy's used to illustrate a common ground when discussing wild/tank raised . I stand corrected on the generalization, but for the most part, did not speak with forked tongue. I will stick to my guns in my own tanks with less current--tastes great issue! Take Care, Joe ;D

[brewmaster15]

I've always been a big fan of extra biological filtration. I like to run 2 aquaclear 500s, and 2 hydro 5s on all my 55 gal, and 75 gal tanks. I've never seen a probelm (except with my electric bill) in my tanks. I agree with Ralph and Tony here,
and Think Dave raises a good point....Muscle mass should increase with the extra exercise....Maybe The fish might have a healthier appetite, but It shouldn't pose a threat to growth, IMO. I guess the ideal thing to do would be to split a spawn, and grow half in sponges with gentle current and half in a tank with strong current and see what happens.

One point to clarify here though... we are talking biological filtration... the filter bacteria can only eat what waste is produced.

Chemical filtration using carbons, resins, membranes etc... those are different, and since the have the potential to remove trace minerals that could be a probelm(even this is debated heavily) . But none of us use that right... we just do our water changes. :)

hth,
al

Joe....

Sorry for the confusion....I wasnt talking about enough current so the fish are "knocked around all day". That would obviously be rather foolish now...wouldnt it...

Its not just a fresh water vs. funky water thing either....they also "play" in the current that the AC makes as the water returns. There are dead spots in the current for them to rest if they so desire.....seems alot of the time they prefer the current.
And yes the tank has sufficient airation/oxygenation.

Just observations Ive made over the last many years...

Tony

[Carol_Roberts]

Hi Jim:
I think a 500 and 300 (each with two sponges inside) would be fine for a 90 gallon tank. There is nothing wrong with the 500 and two sponges - either system should be more than adequate to handle the disolved waste in your tank - especially considering all the water changes we do.
Carol :heart1:

[jim_shedden]

Thanks Carol

Jim