Can you have TOO much filtration?

As the title says, is there such thing as having too much filtration in your tank?

Cheers Stuart.

In theory, no you can’t have too much filtration in an aquarium.
However, if you bear in mind that filtration means flow in the tank, then you may end up with too powerful a filter resulting in too much flow for the size of tank or for the fish in the tank.
Also, some filters such as wet / dry trickle filters are ruthlessly efficient at removing ammonia and nitrates, so may not be desirable in a planted tank for example where plants will benefit from these chemicals.
Essentially the answer is no, but it depends on the set-up you have.

CHeers,

Bill

Ok cheers bill, I'm asking because of a thread i read on here last week about the L/H ratings of filters. it said that when the companies rate their filters power ,its done with out any filter media in the filter and that the actual flow rate may be alot lower than what is stated on the filter.I done some research on this and found that it can be up to 40% reduction in flow rate after a filter is run for 3 days with media inside.So i looked at the standard juwel filter i have on my 110L tank and it was rated for 400L/H, which give me a water turn over of about 3.5 times per/H. add filter media and run for 3 days and that same filter will only turn over my water 2 times per/H if im lucky.So i went and up graded it to a 1000L/H juwel filter which will give me water turn over 5 times per/H. I have the water directed so it doesn't disturb the fish and it gives good water agitation to help oxygenate the water.

Dose that sound ok? or is it overkill?

Cheers Stuart.

That sounds ok to me, you are turning over approximately 6 times the volume of your tank every hour, so that’s fine, assuming that you get a 40% reduction on the flow rate with media.
The key thing with doing as you are, increasing the turnover rate in your tank through the filter is to do so with a larger filter rather than an increased flow rate through an existing filter. Not sure if that makes sense? but the last thing you want to do is to push water too quickly through filter media as this can be counterproductive. It does not allow the bacteria time to act on the water, the water is not in contact with any other media for long enough to allow it to work and even worse, can result in effectively washing the crud from the filter back into the tank.
So in a nutshell, you are doing the right thing by increasing the filter size 6 x turnover is not excessive, even 10x would be ok. Depending on the kind of set-up, such as a river tank, it can be desirable to have a 15 to 20x turnover rate. Once your fish are ok and the current is not too strong, then you are good to go

BillG wrote:

That sounds ok to me, you are turning over approximately 6 times the volume of your tank every hour, so that’s fine, assuming that you get a 40% reduction on the flow rate with media.
The key thing with doing as you are, increasing the turnover rate in your tank through the filter is to do so with a larger filter rather than an increased flow rate through an existing filter. Not sure if that makes sense? but the last thing you want to do is to push water too quickly through filter media as this can be counterproductive. It does not allow the bacteria time to act on the water, the water is not in contact with any other media for long enough to allow it to work and even worse, can result in effectively washing the crud from the filter back into the tank.
So in a nutshell, you are doing the right thing by increasing the filter size 6 x turnover is not excessive, even 10x would be ok. Depending on the kind of set-up, such as a river tank, it can be desirable to have a 15 to 20x turnover rate. Once your fish are ok and the current is not too strong, then you are good to go

BillG you absolutely right.
Its good to increasing filter size (more space for bacteria) but they need time to react.

my 120L juwel had the same 400lph pumpset and it worked with perfect efficency for 5 years non stop (packed it in after them years) but i found it to keep water good. it was also overstocked at times and done 10% w/c every 2 weeks without any fails....
i'd say don't fix whats not broken and its like theory V's my experience!

Unfortunately the answer to the question is Yes. You can have too much filtration.

But it is really the context of what 'filtration' is meant in the question that is important.

Filtration levels is not really measured by output water flow rate of a filter system.....that is simply a statistic on the package.

Often, when people talk about filtration rates, they do tend to refer to the turn-over (volume per volume per hour). In such a case there needs to be a balance between a flow rate through a filter media that will allow sufficient time for the exchange of substrates between water and bacteria, and yet not be too slow as to producing sloughing of the bacterial colony.

If your filtration system is an anaerobic system, then it is not particularly safe to have that run at a level that removes all nitrates from the water (this is not safe to fish)

In an aerobic biological filtration system, the filtration efficiency must be matched to the buffering capacity and RedOX of the water.
Nitrosofication produces nitrous acid, and nitrification produces nitric acid. If these are not buffered in the correct way to produce nitrites and nitrates then you could end up with an acid crash.

So, again, the filtration system needs to be balanced.

What is really needed is an efficient and effective filtration system.....speed in itself is neither of them.

Often these things take care of themselves, but there are many examples of people having an un-explained wipe out.

Ian

..and I note Davey_C's post......... a good mature system like he has and regular partial water changes are actually the key to good water.

ian