Best Way To Migrate Filters?

[JMcQueen]

Im currently running a fluval U3 but plan on switching to a U4 for the extra filtration. The U3 has been established for about 8 months and the bacteria colony handle the tanks load fine. I've put the U4 in the tank so that Im currently running both a U3 and U4 but thinking about it, I doubt a colony will establish in the new filter media of the U4 because it'll never say any ammonia before the U3 removes it.

The ceramic media is easy enough to transfer over but what about the foam? Obviously the U4 is bigger than the U3 so if I just put the foam in the new filter, it wont fill the full cartridge.

 

[joeskandal]

I would have thought running them along side one another for a week or two would be enough to establish new colonies..?

 

[Tizer]

 

[mattbleasby]

I would have thought running them along side one another for a week or two would be enough to establish new colonies..?

+1

 

[Tizer]

you will end up with a fish in cycle if you do that, the baceria colony will never reach a large enough size to cope with the whole tank, why should it, if the other filter is feeding the established bacteria.

Cut the new filter sponges up to allow the old ones to fit. You might get away with just cutting one up, not all of them, if i recall they are only a little taller.

job done.

 

[waterdrop]

Technically you can go about it either way but the scissors are much faster.

It's rather counter-intuitive but it takes a really long time for a second filter to establish itself as well as a filter that has already cycled along with the tank earlier, assuming all you do is just put it in with brand new media. It's not true that it gets no ammonia. It is pulling in tank water so it is getting the same ammonia concentration as the first filter. (In a running tank the bioload (the fish etc.) will supply some constant ammonia load that will be below what our crude test kits read as "zero ppm ammonia.") This concentration is sufficient of course to maintain healthy colonies of bacteria that match the bioload, which is why everything keeps going for years.

The problem from the point of view of the second new filter is that autotrophs don't float around, the new daugher cells stick inside the same biofilm the parent cell in encased in and the whole biofilm is tightly bound to the biomedia just like a stain. So the second filter is beginning it's cycling just like a fish-in cycle but with the system-wide ammonia at an even lower stimulation level because of the cleaning by the first filter. So it can take many more months for the bacteria levels to balance between two filters than it would for a first filter to fish-in cycle. In practice of course it varies a lot because often different filter designs are in use and within-tank circulation is not uniform necessarily for the filter intakes.

If one thinks about which part of the newer bigger sponge (in this case) is the first side to receive water flow inside the filter and cuts a plug (or mulitple plugs) in that side of the new sponge and replaces it with slightly firmly fitting plugs of the mature sponge from the old filter then colonization of the new filter will take place apace! One could envision doing this plug business carefully such that the cut plugs of new sponge could then be also used back in the old sponge and filter so that it would still have good mechanical filtration and could stay in action.

~~waterdrop~~

 

[AstonN24vantage]

+1

 

[JMcQueen]

Does it matter how big the plugs are?

I have to say Im uneasy about the idea of cutting sections in the foam pads and transferring them over. Those things are had to cut accurately at the best of times.

Couldnt the same effect be achieved by compressing the old pad against the new one and leaving them compressed in the filter for a few weeks? If I removed the carbon poly pads I could probably get two pads (compressed) in one cannister. Wouldnt this act to seed the new pad with bacteria and then I could put the established pad back in the smaller filter.

 

[anon02]

The problem with compressing the media is that it restricts flow and reduces the filters` performance, there`s no need for fancy tailoring, just make sure that the water from the intake hits the mature media first

 

[waterdrop]

The problem with compressing the media is that it restricts flow and reduces the filters` performance, there`s no need for fancy tailoring, just make sure that the water from the intake hits the mature media first

Agree.

 

[JMcQueen]

Im actually having a bit of a rethink about this at the moment as the U4 and the U3 are taking up a considerable amount of tank space. What I'm now thinking is to remove and sell the U4, keep the existing U3 and supplement it with an additional U3 or U2.

I known these are simplistic ways of looking at it but:

U4 on its own: 1000 L/H
U3 on its own: 600 L/H

Therefore, as it currently stands I have about 1600 litres per hour of filtration whilst setting the new filter up. The problems are that this takes up a lot of tank space and the seeding bacteria issues above. If I remove the U3 after establishing the U4 I gain 400 L/H

If I add a second U3 and leave the established U3 in place (one on the left and the other on the right of the tank) they don't look too big and I gain 600 L/H over 1 U3 and 200 L/H over a single U4 and avoid cutting sponges etc.

Similarly, a U2 will add 400 L/H and so in conjunction with a U3 I get the same filtration rates a U4, increased surface area of the media sections (U2 and U3 together are bigger than a U4 on its own and it doesnt look too bad in terms of tank space being taken up.

Clear as mud!

 

[Tizer]

wussy

 

[Geoff-]

just take a piece of the old media and put it in the new filter so the water hits the old media first. it will transfer much more efficiently compared with just having 2 independent filters in the tank. the amount of bacteria floating around in the water is minimal.

 

[CrazyAirborne]