Adding A Second Filter, Way To Do It?

[TetraFin]

Hi all!

I'm just wondering if dropping a secondary non cycled cannister filter(fluval u3) into a cycled tank to run alongside a cycled primary pump would cause any problems? I'm unsure as to wether this will cause any kind of spikes or fluctuations with the water whist it is cycling? Does anyone have experience of this?

 

[magical trevor]

As long as your tanks fully cycled IMO i dont think it should matter too much as ive put my fluval (U1) into my tank to cycle for my fry tank. But i would be interested to see what other people think.

How big is the tank?

 

[ScholasticSpastic]

If I understand you correctly, you're asking about adding a new filter to a fully cycled tank while retaining the old filter. If that's the case, you should expect absolutely no problem at all. The old filter is already colonized with bacteria adequate for the nutrient loads of your system. The new filter will become colonized over time- possibly at the expense of some of the bacteria in your old filter.

If the reverse situation were the case- removing one of two older filters to leave a single filter in the tank- you could expect a mini-cycle to result, but I don't think it would be much of one.

 

[Aquascaper]

You won't cause any cycling issues but it will take a long time for it to mature.

If that's the overall plan, to cycle it, the best way to do it is to halve the mature media from the existing filter and put half in each filter. Fill the space created in each filter with new media. This will maintain the filtration capacity and allow the filters to mature a lot faster.

 

[TetraFin]

Okay, thank you guys, I shall add the fluval U3 to my payday shopping list!

 

[magical trevor]

You won't cause any cycling issues but it will take a long time for it to mature.

If that's the overall plan, to cycle it, the best way to do it is to halve the mature media from the existing filter and put half in each filter. Fill the space created in each filter with new media. This will maintain the filtration capacity and allow the filters to mature a lot faster.

But should the water in the tank not cycle it quite quickly as the water in the tank will contain any benificial bacteria i need to seed the filter sponge? Also everything in the tank has bacteria on it from my plants,rock and gravel? I understand the fact that putting it in the main filter will seed it ALOT faster but surely it shouldnt take that long for the U1 filter to seed?

 

[Aquascaper]

Bacteria need a surface to grow on therefore there is minimal beneficial bacteria in tank water, you're correct that gravel, etc. has beneficial bacteria on it but this doesn't 'jump' from one surface to another. You are looking at the difference between 4 - 6 weeks (approx.) until mature if dual running compared to less than a week (approx.) if you share mature media.

For the sake of just taking out some media from the old filter why wouldn't you?

 

[fluttermoth]

There are very, very few bacteria loose in the water column, and a negligible amount on or in substrate and decor.

The bacteria cling on very strongly to the filter media (that's why you can clean it and not wash them all away), so it would take a very long time to mature a new filter that way; if, indeed, it ever became mature enough to cope with the bioload of the whole tank.

 

[magical trevor]

I see. Unfortunatly i wont be be able to split the media because of the size diffrence in the sponge. So ill just jam the small sponge on the U1 inside my rena filter.

Every days a school day

 

[fluttermoth]

Cut the sponge up if it's the wrong size or shape; makes no difference to the bacteria

 

[MikeO]

Great question and responses - I was going to ask the same question!