Thinking of getting a Fluval G6 (media questions...)

[Anne Thynne]

At this point I am pretty confused with all those loooong comments. I was planning to buy a Fluval G6 and then landed on a review ( https://expertaquarist.com/fluval-g6-review/ ). Almost decided I would go for it. My tank is 90 Gallons with moderate bio-load. Can someone simply suggest whether I should buy this canister filter?

 

[ceg4048]

Here's a short comment:

Following the 10x Rule for CO2 injected tanks, a 90G tank will do best with a filter that has an output rating of more or less 900 G per hour.
Are there other brands, or previous versions of this brand (i.e. FX5 or FX6) with similar output that can be had for cheaper?
If no then get this filter. If yes then get something else.
Filters are nothing more than plastic buckets with a pump attached. All the electronic wizardry being implemented on modern designs are all illusions.
What really matters is the muscle of the pump in the bucket and it's durability/reliability. Everything else is fluff.

Cheers,

 

[alto]

I'm not as convinced of the 10x "Rule" - good flow is not synonymous with high flow rate

You can look at many successful Tropica & ADA planted tanks where filter (manufacturer stated) flow rate is only 4-5X tank volume (ie total volume - obviously the addition of substrate, hardscape & plants, can substantially lower the actual water column volume)
Important Note: these tank examples usually run without any of the inline filter modifications that are so popular now
If you're planing inline heater, CO2 reactor etc, then expect to buy more filter power, or run these off a secondary filter

But even I would not attempt to run a 90gal tank with a single G6 - which Fluval lists 1000litre/hour turnover, maximum possible!

You don't mention tank dimensions, but I'd choose 2 filters rather than attempt a single larger filter
(I've not been impressed with the 3 FX6 filters a friend runs on bigger (goldfish) tanks)

I was quite keen to see the G6 after watching George Farmer videos
Until I saw the local shop price (or even best online price I could find) - I could buy 2 Eheim Pro's complete with media for slightly less
After playing with the instore demo filter, I was even less inclined - some of the components are much lower grade material/manufacture finish than I'd consider at that price

You could source a used G6, but then you're (likely) out of warranty & I definitely would not purchase without testing it first

 

[Wookii]

Sorry for digging up an old(er) thread but I figured this may have the most owners in it.

I'm considering replacing my Eheim 2028 with a filter that allows easier cleaning via a dedicated and easily removable pre-filter. I've already had enough of regularly having to completely disassemble my Eheim to clean it.

Current candidates as the Oase Biomaster 600, the Aquel Ultramax 2000, and the Fluval G6. I have largely discounted the Aquel, as I'd have to physically move it every time I needed to remove the pre-filter due to the tight-ish space it will be housed in.

That leaves the Oase and the Fluval.

So on the Fluval, I have a few questions:

1. How are owners finding it after long term use? Still happy with it? Any issues?
2. On the secondary chemical filter, can this be replaced with the finer 75 micron pre-filter that Fluval sell? Has anyone any experience with this finer pre-filter cartridge?
3. Does anyone use Purigen in the secondary filter so it can be easily removed for recharging? (I appreciate the Purigen is usually kept at the very end of the filter cycle, but easy removal of this for monthly recharging is attractive).
4. If I understand correctly the pre-filter filters from the inside to the outside. Doe this mean that should any shrimp etc get sucked into the filter, they will be safely caught inside the pre-filter cartridge for later repatriation? Anyone had this happen?
5. Am I likely to see any flow difference between my existing Eheim 2028 and the G6?

 

[Andrew Butler]

That leaves the Oase and the Fluval.

I'm a lover of the G6 filters, the only thing they're missing is the built in heater.

I have also had an Oase filter, simply as I wanted the built in heater convenience.
From experience flow from the Oase Biotherm 600 is a trickle compared to the G6 - simple as that. I tried changing back to the G6 as I just didn't think flow was very strong and using the exact same spraybar etc the G6 blasted the soil away and ruined the scape so had to change things a bit. The Oase pre-filter is awful also, to get it out you need a VERY tall cabinet or remove the filter from the cabinet which is a pain. Those two points alone were enough to put me off the Oase - I've no idea why they are so heavily backed by retailers; money maybe?

So on the Fluval, I have a few questions:

1. I've had quite a few of these filters and before I closed some aquariums down had 4 of them running at once. There's now only one in the house which will also be coming to a stop in the not too distant future as changing to an AIO system so everything is contained within the aquarium so no hoses to tackle.
2. The pre-filter cartridges will fit the mechanical section only. I did try one of the finer pre-filters in the mechanical section but it did restrict flow after several months where things had just clogged it up despite keeping them clean so save your money and stick to the normal ones. I've hard water so was possibly due to that.
The chemical cartridge provided is full of carbon but you can take the covers off and providing it's appropriate put what you want in there.
3. I did use Purigen very briefly but seem to favour activated carbon myself, why? - who knows but think it's the cleaning of the Purigen and how easy it is to use a good quality activated carbon such as Rowa Carbon and not all that expensive. *I had previously added Purigen directly to the chemical cartridge which I read people had done but was a very bad idea, the cartridge slots are not fine enough so stick to putting it in bags first!
4. Yes, flow goes from the inside to outside of the pre-filter so things get caught within the inside of it, including lots of shrimp 'safely' I'm unsure is the correct word as the flow is still going into the pre-filter but providing you rinse it with each water change then you should be ok; I've only ever had a handful of dead babies.
There's an art to cleaning the pre-filters and I found the brush most suited to using the handle to tap the cap out of the pre-filter and noting more! Once you've tapped the cap out over a small bucket you will be able to tap the shrimp out that haven't fallen already and found the best way of cleaning them was to just use a hose or shower on the jet type setting and blast it from the outside if this makes sense?
5. No experience of the Eheim 2028 but can compare the Oase as I have above. They say the 'pump performance' is 2460 LPH and actual flow rate of the G6 is 1000 LPH.

One thing I would say as a big negative about the G6 is Fluval advertise you're able to regulate flow with the Aquastop lever without harm to the motor etc which is not true and I've had a couple of the filters unable to reach full flow after running them at reduced flow while things were settling in. Hagen (UK) did replace them for me but I was told the valve regulation is meant for such times as feeding alone which it makes no mention of anywhere on the dedicated G-series website.

Quote from webpage:

'With its proprietary technology the AquaStop system makes maintenance easy, allowing you to stop the water flow by simply bringing the AquaStop valve lever into an upright position. By lifting the AquaStop release lever, the complete assembly can be conveniently removed without separating the hosing. The AquaStop valve lever can also be used to regulate the water flow with no harm to the motor or its components.'

I'd choose the G6 personally but that's just my opinion.

If you do go down that route and need any spares give me a shout as I've got loads I'll be selling when the other one is shut down and sold on.

 

[Wookii]

I'm a lover of the G6 filters, the only thing they're missing is the built in heater.

I have also had an Oase filter, simply as I wanted the built in heater convenience.
From experience flow from the Oase Biotherm 600 is a trickle compared to the G6 - simple as that. I tried changing back to the G6 as I just didn't think flow was very strong and using the exact same spraybar etc the G6 blasted the soil away and ruined the scape so had to change things a bit. The Oase pre-filter is awful also, to get it out you need a VERY tall cabinet or remove the filter from the cabinet which is a pain. Those two points alone were enough to put me off the Oase - I've no idea why they are so heavily backed by retailers; money maybe?


1. I've had quite a few of these filters and before I closed some aquariums down had 4 of them running at once. There's now only one in the house which will also be coming to a stop in the not too distant future as changing to an AIO system so everything is contained within the aquarium so no hoses to tackle.
2. The pre-filter cartridges will fit the mechanical section only. I did try one of the finer pre-filters in the mechanical section but it did restrict flow after several months where things had just clogged it up despite keeping them clean so save your money and stick to the normal ones. I've hard water so was possibly due to that.
The chemical cartridge provided is full of carbon but you can take the covers off and providing it's appropriate put what you want in there.
3. I did use Purigen very briefly but seem to favour activated carbon myself, why? - who knows but think it's the cleaning of the Purigen and how easy it is to use a good quality activated carbon such as Rowa Carbon and not all that expensive. *I had previously added Purigen directly to the chemical cartridge which I read people had done but was a very bad idea, the cartridge slots are not fine enough so stick to putting it in bags first!
4. Yes, flow goes from the inside to outside of the pre-filter so things get caught within the inside of it, including lots of shrimp 'safely' I'm unsure is the correct word as the flow is still going into the pre-filter but providing you rinse it with each water change then you should be ok; I've only ever had a handful of dead babies.
There's an art to cleaning the pre-filters and I found the brush most suited to using the handle to tap the cap out of the pre-filter and noting more! Once you've tapped the cap out over a small bucket you will be able to tap the shrimp out that haven't fallen already and found the best way of cleaning them was to just use a hose or shower on the jet type setting and blast it from the outside if this makes sense?
5. No experience of the Eheim 2028 but can compare the Oase as I have above. They say the 'pump performance' is 2460 LPH and actual flow rate of the G6 is 1000 LPH.

One thing I would say as a big negative about the G6 is Fluval advertise you're able to regulate flow with the Aquastop lever without harm to the motor etc which is not true and I've had a couple of the filters unable to reach full flow after running them at reduced flow while things were settling in. Hagen (UK) did replace them for me but I was told the valve regulation is meant for such times as feeding alone which it makes no mention of anywhere on the dedicated G-series website.

Quote from webpage:

'With its proprietary technology the AquaStop system makes maintenance easy, allowing you to stop the water flow by simply bringing the AquaStop valve lever into an upright position. By lifting the AquaStop release lever, the complete assembly can be conveniently removed without separating the hosing. The AquaStop valve lever can also be used to regulate the water flow with no harm to the motor or its components.'

I'd choose the G6 personally but that's just my opinion.

If you do go down that route and need any spares give me a shout as I've got loads I'll be selling when the other one is shut down and sold on.

Thanks for the detailed response Andrew, that’s hugely appreciated.

In terms of controlling the flow, could I simply use the ball valves in the Eheim quick release connectors that I already have in place, or would this put undue pressure on the motor?

I want to go with the G6 as I hope to upgrade to a larger tank in a year or so, but for now I don’t necessarily want to turn my little 60 litre tank into a washing machine.

I’m assuming the difference between the 1000lph (considering it’s 2460lph motor) rating of the G6 and the 1250lph rating of the Oase 600 is simply because the latter is also a motor rating, whereas the former is with the canister full of media?

If I was adding Purigen to the chemical cartridge, would I not be able to just insert the standard pre-bagged ones (rather than loose), or would they not fit?

 

[Siege]

I use a G6 filter regularly.

amazing pump.
Bugger all room for media
Horrible brittle plastic that hurts your fingers everytime you touch it!

I’m not being much help I’m afraid.....!

 

[Andrew Butler]

In terms of controlling the flow, could I simply use the ball valves in the Eheim quick release connectors that I already have in place, or would this put undue pressure on the motor?

In italic below is an email quotation from the senior aquatic technical advisor at Hagen UK. I asked for something in writing when I was first told it was my fault for running the filter with the aquastop lever partly closed to control flow and had damaged the motor by doing this, which as you can see completely contradicts the information given by Fluval on their G-Series website; information included at many places online as a feature and I think it's even on the box (this I'd have to check and it's in the loft)
I did get a refund/replacement but only after pointing out how it's an advertised feature of the device and nowhere within the instructions does it mention possibility of damaging the filter and infact quite the opposite. Unsure their handbrake analogy is the best
'As per our conversation regarding the flow lever, all our externals filters can have the flow reduced for maintenance and feeding times but should not be permanently restricted, this is why we do not recommend the in-lining of any product as this will restrict flow. Permanent restriction may compromise the efficiency and durability of the filter as would a car hand brake if you were to drive with it half on.'

I want to go with the G6 as I hope to upgrade to a larger tank in a year or so

There's always the G3 if you want something smaller, depends how much bigger the other tank could be.

I’m assuming the difference between the 1000lph (considering it’s 2460lph motor) rating of the G6 and the 1250lph rating of the Oase 600 is simply because the latter is also a motor rating, whereas the former is with the canister full of media?

From what I was told it's to do with resistance from media, head loss etc but if the graph on screen shows full flow then it should be running an actual 10000 LPH.
No idea about other stated filter turnover rates and how they deliver compared to stated - I think that's a whole different topic.

If I was adding Purigen to the chemical cartridge, would I not be able to just insert the standard pre-bagged ones (rather than loose), or would they not fit?

Yes, just use an empty media chamber to put the bag in (essentially empty the carbon and put the bag in)

Bugger all room for media

serious question - how much should you have?

Horrible brittle plastic that hurts your fingers everytime you touch it!

If the prime pump gets stuck that area is a bit of a nuisance as can the priming then which is the only place I ever find the plastic annoying. Where do you find it brittle Steven?