1 litre of media per 25l of tank water

[Lo1]

This is an interesting video:

[plankton]

I always "over-filter" (at least the "next size up") tanks to make sure most of the "munchers" are in the filter and not on the "hardscape".
We know that the advertised filter rates are not the rates you get in the tank, so this vid makes sense to me.

[Lo1]

I always "over-filter" (at least the "next size up") tanks to make sure most of the "munchers" are in the filter and not on the "hardscape".
We know that the advertised filter rates are not the rates you get in the tank, so this vid makes sense to me.

100%.

The hardscape is just that.

The filter should be sufficient to filtering the tank.

Interestingly the Eheim 5e 450 that I had held 2 1/2 kg, which was not enough for my tank. But the F Zone (which is the same size as the eheim) holds 4 1/2 kg.

[SPACKlick]

I'm not sure how well he understands the biological filtration in our tanks from that video. Bare Glass tanks can provide enough surface for munchers for most sizes of tank. Substrate and decor increases that many fold. Sponges, even 20 PPI sponges are great filter media, in many ways better than ceramics and sintered glass. The main purpose of the cannister filter is to provide consistent turnover of oxygenated water with the NH4/NO2.

His 1L/25L ratio for biofiltration is plainly false. I have about 4L of what he would consider Biological Filtration on my 250L tank at the moment that's around 109% stocked by aqadvisor. I've run the same tank on 1L of biological media with a different, similarly full, stocking. All of the foam provided with the FX6 works excelently as filter media and it's designed in such a way that it actually uses all the filter media unlike some canisters that bypass a lot of it.

That being said, I wish more filter manufacturers would be honest about the flow rate. For a standard fisthank I'd usually consider flow rates of about 4turnovers per hour. For a heavily planted tank, in order to get nutrients and oxygen well distributed the general rule is turnover 6 to 10 times per hour. FX6 markets based on 3,500 litres per hour. In the paperwork it says 2,130 litres per hour circulation rate. Actual measured output varies between 1,750 and 1,965 litres per hour. That's as low as half. My EX1200's are lower than that. Getting around 550 (although I have significantly adjusted contents).

So FX6 is appropriate for 175L heavily fertilised planted tanks to 450L fish tanks but it advertises itself for 1500L tanks. I'd be interested to see someone running a 1500L tank reasonably heavily stocked running just an FX6. I don't doubt it would handle the Nitrogen cycle (As I said, bare tanks with little flow can do that) but the tank would probably be far from clean and oxygenation could end up being an issue. But it would be interesting to see.

[Lo1]

Isn’t that the truth?

My old eheim 5e 450 is rated at 1700l. The web dashboard that you use with it, never showed more than 905l. After a few weeks it has been as low as 450l.

This is why I went over to the 15l F Zone and swapped out the pump for an aqua medic. I am only running it at 65%:





Aqua medic states not to run the pump at less than 60%. In order to give it a little leeway, I’m running out at 65%. But as you can see, the flow is fantastic at 65%.

[black ghost]

I'm not sure how well he understands the biological filtration in our tanks from that video.

He doesn’t, really. He’s filling a canister with Siporax and no sponges to keep it clean. He’s totally missed the point of porous media, and needs to use a lot more than most people because of it. I could keep a tank twice that size on the amount of media he thinks he needs. Still, it sells more media.
Also, different media have different surface areas. I litre of one could be equivalent to 10 litres of another. It’s easy to see why he goes for such overkill. The media supplied with filters usually isn’t the best, and Siporax used the way he uses it will be no better.

[Stephen]

I do not use sponges as Biological Media, I use them as Mechanical filtration.
My Biological Media houses the beneficial bacteria.
I use the quality Eheim SubstratPro biologocal media (I swear by it).
The Sera Siporax ceramic rings are a good biological media, probably the best 'ceramic ring' type media, but not as good as other brands such as my Eheim SubstratPro (sintered glass media).
My Eheim Pro4 600s are rated at 1250L/h but with great Biological Media capacity and great Eheim SubstratPro biologocal media provided.
I swapped out the Eheim MechPro for Eheim Mech and swapped out the tray of Eheim BioMech or an additional tray of Eheim SubstratPro.
I now rate my Eheim Pro4 600s as suitable for aquariums of around 240L-350L with the current media set up.
I have 2 x Eheim Pro4 600s on my 425L aquarium.

The Fluval FX6 (as in video) is a great filter but the biological media is poor and despite the size of the filter the amount of biological media it holds is also poor.
As with all Fluval external filters, the mechanical media (sponges) are good but the biological media let them down and need upgrading.

[SPACKlick]

I do not use sponges as Biological Media, I use them as Mechanical filtration.

It doesn't matter if you use them as biological media or not, the bacteria do. Aerobic Bacteria grow better in 20-30ppi sponges than they do in sintered glass and ceramics from everything I've seen and from personal experience with small internal filters.

As with all Fluval external filters, the mechanical media (sponges) are good but the biological media let them down and need upgrading.

I hard disagree, I've seen someone run an FX6 on 100% foam and heavy load (C. 350L with around a couple of dozen Fancy Goldfish) and, once they added an intake sponge, that filter kept the water pristine clean and the nitrogen cycle fully handled. All the expensive Biomedia; {Substrat, Matrix, BioHome, Alfagrog, Bioballs} are, in my experience, pretty poor as homes for munchers with Ceramic rings being pretty much the worst. I can't find anything in the scientific literature to support any static media as more effective than sponges.

[black ghost]

The Sera Siporax ceramic rings are a good biological media, probably the best 'ceramic ring' type media, but not as good as other brands such as my Eheim SubstratPro (sintered glass media).

Siporax is not ceramic. It’s sintered glass. It has the same surface area as Substrat pro.

[black ghost]

Ceramic rings are designed as a prefilter. Fine sponges have a larger surface area, so are better for housing bacteria. Porous media are no better than ceramics unless they’re kept scrupulously clean. Then they come into their own, housing many more bacteria than sponges.