Over Filtration?

[aussieant32]

Hi all!

I have been keeping tropical fish for about 7 years. I am about to set up a new discus tank. I kept them a few years back but had to move and leave tank behind. I have been given a 30g tank with an internal undergravel filter and and external canister filter, im not sure of filter turnover etc but they have had it set up for about 4 years and have not had any filtration problems, also the guy donating it to me knows what he is doing so id imagine its fine.

Now i know discus need quite good water conditions, so i was wondering, can i over filter the tank?

The reason i ask is that the canister filter has quite a small intake at one end, would it be worth putting a internal filter at the opposite end or would it take too much out of the water? Also would it worth keeping the undergravel or removing it?

Thankyou for any help!!

 

[saz326]

"over filtration" is quite a neat trick when a tank is overstocked as it enables the water conditions to be maintained at good parameters while far too many fish have been fitted into a tank. It is also a good tool for ensuring that the filtration you have is adequate to cope when fish start breeding and numbers rise.

It is practically impossible to actually filter too much (which is what I think you meant by over filtering). A filter (no matter how big it is) will only contain/sustain enough bacteria to deal with the current quantity of fish waste being produced. By having a larger filter there is room for the bacteria colony to grow if you add more fish stocks or start to suffer from decaying fish/plants/overfeeding.

There is posibility that you could cause the water flow rate to be too fast for the fish to comfortably live in. They dont wanna be running all day trying to keep up with the water flow in the tank.

..you say the tank has an undergravel filter as well as canister. There is a little concern with undergravel filters that after a while the debris caught in them can build up and you can suddenly face water problems. Once set up they can be a pain to clean out so if possible I would remove the undergravel system.

 

[aussieant32]

ok, i will remove it, im getting the tank empty, so i will remove it, so do you think it would be worth getting an internal as well or just stick to the canister?

 

[kingkano]

Are you planning to keep discus in this 30g tank? I think it might be a bit small. Except perhaps maybe for a mated pair or some little ones that will be moved onto a larger tank in 12mths?

ANd you definitely can't filter too much. especially for discus

 

[ALW]

It is practically impossible to actually filter too much (which is what I think you meant by over filtering). A filter (no matter how big it is) will only contain/sustain enough bacteria to deal with the current quantity of fish waste being produced. By having a larger filter there is room for the bacteria colony to grow if you add more fish stocks or start to suffer from decaying fish/plants/overfeeding.

Agreed!

 

[aussieant32]

i will more than likely be upgrading in size, i have a 6ft tank in storage but where im living at the moment i cant fit it, i am planning to be in a new place in 12-18 months time so it should be fine. I have a Ehiem 2213 for the tank at the moment so i may put another internal up the other end just to help out, thanks for all the help!!

 

[meguro]

Wouldn't too strong of a current be a possibility of over filtering? Now while that doesn't have anything to do with the actual water quality, it is still something to consider.

But going with water quality, reverse osmosis and deionisation are surely ways of filtering a tank? Too much water of this quality (near perfect h2o), lacks essential trace elements and minerals.

So technically, it is possible to over filter.

 

[kingkano]

Wouldn't too strong of a current be a possibility of over filtering? Now while that doesn't have anything to do with the actual water quality, it is still something to consider.

But going with water quality, reverse osmosis and deionisation are surely ways of filtering a tank? Too much water of this quality (near perfect h2o), lacks essential trace elements and minerals.

So technically, it is possible to over filter.

Too strong a current can be a problem but spray bars sort this. But thats not necessary filtration. thats flow. powerheads for example would give flow but no filtration alone.

RO and DI aren't tank filtration. They are water preparations. Yes too much pure water would be deadly. It wouldnt hold oxygen and other minerals etc. Which is why you either mix your RO/DI with some tap, or preferably use one of the ready prepared remineralisation powders. You add these as per the instructions to RO water to give you the perfect mix for your situation. This is a salt mix for marine, a general trop mix or a discus mix for example.

Technically its impossible to over filter as already pointed out, because you will only end up bacteria to digest whatever ammonia/nitrite are generated. But you can have too strong a flow

 

[aussieant32]

all great information, the output for the canister is a spray bar and the internal filters all come with the 'funnel' output thats supposed to reduce flow. the canister turns over 400l/h so its probably enough, i do weekly water changes too, might look at an internal but will definately remove the undergravel as i want it quite well planted so i dont want root issues

Thanks a bunch guys, great help!!

 

[meguro]

RO and DI aren't tank filtration. They are water preparations.

They're still methods of filtration.