Hardy Fish - Practically No Filter!

[The Duke]

The millions spent on expensive filters and media and this guy has perfect stats with nothing other than his water and fish.....and here is me religiously changing water and filter pads haha there is a moral in this story somewhere that I need to figure out!

 

[FishBlast]

The millions spent on expensive filters and media and this guy has perfect stats with nothing other than his water and fish.....and here is me religiously changing water and filter pads haha there is a moral in this story somewhere that I need to figure out!

And I'm planning on getting another internal filter. Well, it does its job, even though some of my ramshorns prefer to live in it and every month I have to put each snail back in the tank when I clean the sponge. But just in case it dies on me, I'd rather have a spare.

 

[4seasons]

Hmmmmmm, so when a LFS told me that the good bacteria grows in the gravel instead of the filter the lady may have been telling me truth?
No a LFS telling my truth, can't be. There must be more to it than this.

 

[ZoddyZod]

very very interesting.

That tank certainly doesn't look like it contains enough plant life to replace the baceria colony of a filter. My guess is that there is enough surface area within the filter housing for a colony to have established. Bacteria doesn't have to live on ceramics or sponges (which are plastic themselves) so they might just be surving on the filters internal features......that's my guess anyway.

 

[mrlewis1978]

My guess too Zoddy. Water still all ok this morning and inhabitants happy. Looks like nature looked after them on this rare occasion.

 

[Prime Ordeal]

very very interesting.

That tank certainly doesn't look like it contains enough plant life to replace the baceria colony of a filter. My guess is that there is enough surface area within the filter housing for a colony to have established.

An empty filter would have nowhere near enough surface area to process the bioload of this tank. No, it's just a simple matter of the plants eating the toxins along with the bacteria on the tank, filter, substrate and plants. I don't find it all that surprising.

There must have been a spike during the transition from using the initial cycled filter to using the empty one though.

 

[Prime Ordeal]

Hmmmmmm, so when a LFS told me that the good bacteria grows in the gravel instead of the filter the lady may have been telling me truth?
No a LFS telling my truth, can't be. There must be more to it than this.

They're absolutely telling the truth. The surface area of the substrate can be anything up to half of the surface area of filter sponge (for equal volumes), for example, and there's usually more substrate than filter media.

What the substrate lacks is adequate flow and oxygenation so its potential maximum efficiency isn't realised.

Nevertheless, despite what some would have you believe, there is a substantial amount of active nitrifiers in the substrate.

 

[ZoddyZod]

in terms of plant life in that tank - I personally don't think there is enough in there to be playing a major part in the processing of any ammonia.....a few vallis and an anubius don't seem up to the task for the stocking, in my opinion.

I do agree that the substrate could be housing enough bacs though.....but as you say, it depends on the flow that the substrate is receiving. Given the filter is an internal with a outlet positioned near the top of the tank, I'm surpirsed that this seems to be the case.......but stats don't lie (well, mostly).

again.....very interesting to see results like this that go against our common perceptions of what is required.

 

[Prime Ordeal]

in terms of plant life in that tank - I personally don't think there is enough in there to be playing a major part in the processing of any ammonia.....a few vallis and an anubius don't seem up to the task for the stocking, in my opinion.

Sure, I was only saying that the plants make up part of the whole nitrogen absorbing mass, not that they were necessarily the greater part of it.

 

[tomtomtom1230]

would the bacteria not have just grown on the walls of the filter? I'm surprised your water has been clear though, mine wouldn't have been

 

[ZoddyZod]

would the bacteria not have just grown on the walls of the filter? I'm surprised your water has been clear though, mine wouldn't have been

some will have done, what's unknown is if that surface area is enough to provide the space required for a bacteria colony capable of handling that bioload or (as PO states) if some was also spread on the substrate etc.

 

[Prime Ordeal]

I'm not trying to be argumentative ZoddyZod but it is certain that the surfaces of the filter (i.e. without media) are insufficient, otherwise we wouldn't need media-filled filters would we? Or are you suggesting that it's a marketing ruse by the companies to sell sponge and floss?

Actually I wouldn't be too surprised if it was.

 

[ZoddyZod]

don't worry, I'm not taking it that way.

I'd be surprised myself if the filters internal surfaces were enough, but then this whole 'incident' is quite odd and goes against what we all think is the norm and what SHOULD be the minimum for a bacteria colony.

Who knows, maybe the stocking is small enough for it to perform this way......but it would be good to understand quite how strong the flow is at the base of the tank and across the substrate.

 

[Prime Ordeal]

The easiest way to think of it is this. Imagine you changed nothing in the tank except the filter system, so we ditch the original filter and introduce an under-gravel filter. You know as well as I do that the filtration provided by the substrate would be perfectly adequate for any normal stocking.

The only difference from that here is that the flow is limited to the top top one or two centimetres of the substrate and the flow rate is much less, but it still provides a sizeable amount of surface for nitrifiers to adhere to and do their thing.

The specific surface area of a typical foam is about 400m[sup]2[/sup]/m[sup]3[/sup], and the SSA for a smallish gravel is about 150m[sup]2[/sup]/m[sup]3[/sup], so volume for volume gravel has about a third of the surface area of foam and there's usually a lot more substrate than media.

And clearly it is tank specific as each will have different media, substrate and flow rates across the substrate.

So what works in one may not work in another superficially similar tank set up.

 

[ZoddyZod]

as a complete aside, up until quite recently I ran an overstocked tank with two external filters. Out of the 7 buckets available for media, I only filled one with ceramics (wanted the higher flow)......never had a water quality issue.