Two Filters - Double The Bacteria Colony?

Hello everyone

I've just added a second filter to my 180 litre / 47 USA gallon long.

I now have an Eheim Ecco Pro 200 external and a Juwel Bioflow internal with a 600 pump. So both filter at 600 litres per hour.

Assuming there's sufficient ammonia generated by the fish stocked - will I end up with two full bacterial colonies in each filter?

 

Yep. And that covers you if one of the filters stops working unexpectedly or if you need to it set up an emergency hospital or quarantine you can borrow one of those established filters for an instantly cycled QT.

I am a big fan of having two filters on a tank.

 

I am a big fan of having two filters on a tank.

So am I.

 

The bacterial colonies will only grow to the size of the food provided - so two filters would split the bacteria evenly. The colonies can expand rapidly though, so if one filter failed or was removed, the other would recover enough to handle everything fairly quickly, so long as there was enough media and water flow. You might see a slight blip in the cycle though.

 

Bacteria can’t double, unless somehow your bioload has doubled as well. I agree that adding another filter will simply distribute the bacteria colonies evenly.

 

Ya, I took that too literally.
Its not two full colonies, it is still the same amount of BB, its split between two filters.

But still, it gives you back up if one fails and it gives you a spare for emergency set ups.

 

Appreciate the guidance everyone - thank you!
I also like the idea of the safety net of the 2nd filter.
Over the coming weeks, I plan to increase my stock by 8 fish. Plus 4 more KuhlI Loaches.

 

Bacteria can’t double, unless somehow your bioload has doubled as well. I agree that adding another filter will simply distribute the bacteria colonies evenly.

Doesn't it have to do with "housing"space as well? Isn't the bioload answer an assumption? Not meand in a rude way btw

 

Hi, you’ll only ever have as much beneficial bacteria as is needed to process the existing bioload.
Having 2 Filters won’t necessarily mean each filter contains half the bacteria, there’s no telling how much BB will be in each filter, it could be split 75/25 or 60/40 but it does mean if one filter goes down there'll be some back up in the other.

 

Doesn't it have to do with "housing"space as well? Isn't the bioload answer an assumption? Not meand in a rude way btw

You’re right. It is an assumption (as far as I know), but one based on logic (at least I think so). Housing space is a good point. I guess that depends on how much room the media has for bacteria to colonize to start with, so adding a second filter may or may not be an additional advantage in terms of more bacteria. I don’t have a good answer to that.

Hi, you’ll only ever have as much beneficial bacteria as is needed to process the existing bioload.
Having 2 Filters won’t necessarily mean each filter contains half the bacteria, there’s no telling how much BB will be in each filter, it could be split 75/25 or 60/40 but it does mean if one filter goes down there'll be some back up in the other.

Good point. I’m sure a lot of the split depends on filter flow.