# Fluval Canister Filter size



## minorhero (Mar 28, 2019)

jdwebb1 said:


> First tank, 20 gallon long, low profile tank. The 207 is rated for 20-45 gallons. Tank will be scaped, shrimp and schooling fish, Controsoil planting material over inert gravel. Does anyone have experience with the Fluval 207? Will it be enough or should I be looking at the 307 40-70 gallon? Thanks.


This would be greater then 10 times per hour turn over. If it actually performed 10 times per hour it would be too powerful for a 20 gallon tank. Assuming you put it on the floor and the tank on a stand it should reduce the flow out of it enough that it will not be too much, hopefully. Good thing is you can always turn it down if needed through a ball valve (if it doesn't come with a solution). I have never used one so I can not give you first hand experience. But generally you want between 4 - 8 times tank turn over.


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## DaveKS (Apr 2, 2019)

If you look at specs on fluval page they give filter circulation, which is actual throughput you can expect when pushing average tank head height and filled with media. 207 is 121gph. In that shallow a tank that should be fine, that’s 6x+ turnover. That 121gph will be blowing plants sideways close to output.

The problem with that long skinny tank is coverage, you’d be well advised to use a Y on output and split to 2 outputs, one top left blowing down back wall left to right aimed slightly downwards for high->low circulation and other top right, right at surface to give surface ripple/gas exchange and angle it slightly to left so it moves water down front wall right to left. 

Even though you’ve split to 2-65gph outputs, which might sound weak, it’s really not in the 12x10 area you’ll end up with in that tank once gravel is added. The two will work together to make a nice slightly brisk but not overbearing rotating current in tank that should be just right.


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## jdwebb1 (Aug 26, 2019)

DaveKS said:


> If you look at specs on fluval page they give filter circulation, which is actual throughput you can expect when pushing average tank head height and filled with media. 207 is 121gph. In that shallow a tank that should be fine, that’s 6x+ turnover. That 121gph will be blowing plants sideways close to output.
> 
> The problem with that long skinny tank is coverage, you’d be well advised to use a Y on output and split to 2 outputs, one top left blowing down back wall left to right aimed slightly downwards for high->low circulation and other top right, right at surface to give surface ripple/gas exchange and angle it slightly to left so it moves water down front wall right to left.
> 
> Even though you’ve split to 2-65gph outputs, which might sound weak, it’s really not in the 12x10 area you’ll end up with in that tank once gravel is added. The two will work together to make a nice slightly brisk but not overbearing rotating current in tank that should be just right.


Was also considering a ball valve to reduce flow, but wonder if it might tax the pump in any way. Thanks for the advise, will surely make note of it.


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## DaveKS (Apr 2, 2019)

jdwebb1 said:


> Was also considering a ball valve to reduce flow, but wonder if it might tax the pump in any way. Thanks for the advise, will surely make note of it.


With 207 you for sure won’t need valve, especially if you split to two outputs. Now if you go up to 307 at 206gph throughput might need valve to cut flow a bit. 

But it’s fine to use valve on output side.


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## goodbytes (Aug 18, 2014)

jdwebb1 said:


> Was also considering a ball valve to reduce flow, but wonder if it might tax the pump in any way. Thanks for the advise, will surely make note of it.



You can cut the flow by up to 50% at the AquaStop valve that comes with the canister. The Fluval manual states that 50% reduction is the maximum recommended by the manufacturer but it can be adjusted lower than this.


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## Quint (Mar 24, 2019)

IMHO after putting a 307 on my 40B the 207 will be more then adequate for a 20L. If I turn the 307 up all the way it will blast the plants around. I run it reduced via the hunky dory throttle control they use. Dont waste your money on going way overboard and use it elsewhere. 

Of note remember the hoses on these are that weird corrugated (?) type, almost like they want you to only buy hoses from them or something. Anyhow modding is difficult such as adding a ball valve which with regular tygon is as simple as a cut and two hose clamps.


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## jdwebb1 (Aug 26, 2019)

Quint said:


> Of note remember the hoses on these are that weird corrugated (?) type, almost like they want you to only buy hoses from them or something. Anyhow modding is difficult such as adding a ball valve which with regular tygon is as simple as a cut and two hose clamps.


I see the hose size is 14.5mm, inside diameter I assume, which makes it hard to find a clear vinyl hose to replace it. The intake and output fittings are very displeasing to look at and will be difficult to hide among the plants. I can't even find glass lily pipes that will fit. Shame on Fluval if this is the case, I should have done more research I guess.


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## Quint (Mar 24, 2019)

jdwebb1 said:


> I see the hose size is 14.5mm, inside diameter I assume, which makes it hard to find a clear vinyl hose to replace it. The intake and output fittings are very displeasing to look at and will be difficult to hide among the plants. I can't even find glass lily pipes that will fit. Shame on Fluval if this is the case, I should have done more research I guess.


It can be changed out which is what I am doing. From what I have read 5/8"ID 7/8"OD tubing should work fine. The thinner walled tubing can work but kinks easier apparently. Thats what I am doing. Will see how it goes. Ive got my spray bar built and the new suction line built, all painted. I just need to flush them out and hook everything up. May get it done tonight if I get a few minutes. 

Yes I agree the tubing they come with is very annoying. Not to mention it builds up stuff inside and when repriming the filter I usually get a blast of stuff into the tank. Fish like it but its annoying.


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## novato (Aug 22, 2019)

In order to install an inline co2 diffuser I've replaced my Fluval 305 ribbed return hose with 5/8" id heavy duty clear vinal tubing from Home Depot, and so far it has no leaks with ss hose clamps. The canister hose end had to be warmed with a heat gun to be pushed on.


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## ipkiss (Aug 9, 2011)

yep. like posters above me, 

eheim 16/22mm ~ 5/8" ID vinyl tubing

you need to consider the ID of the ugly white adapters and not so much the ribbed hose, since that's what's going over the equipment barbs.

think I read the cheap sunsun tubing for hw-302 works too
https://www.plantedtank.net/forums/9-equipment/177543-sunsun-hose-size.html

https://www.amazon.com/Replacement-Flexible-Tubing-SUNSUN-Canister/dp/B00NI4NMI2

couple bucks extra and you get a slew of fixtures too that might help

https://www.amazon.com/SUN-SS303AK-Hw303Ak-Aquarium-Accessories/dp/B00NI4OVPU


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## Mostro (Aug 26, 2012)

DaveKS said:


> If you look at specs on fluval page they give filter circulation, which is actual throughput you can expect when pushing average tank head height and filled with media. 207 is 121gph. In that shallow a tank that should be fine, that’s 6x+ turnover. That 121gph will be blowing plants sideways close to output.


Would this still be the case with a Cerges reactor (RO filter housing) and an in-line heater on the 207 outflow? Not sure how many gph of circulation these items would scrub off, but it seems like the 207 might be borderline on a 20 gallon tank with this setup and I wonder whether a 307 would be a better choice due to the added resistance?


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## Shazwazer (Jan 28, 2011)

I had a fluval 207 on a 29 gallon tank and felt the need to upgrade to a 307. Depending on your head height i don't think it will be too much for a 20 gallon especially if you run it through a spray bar to disperse the flow.


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## DaveKS (Apr 2, 2019)

Mostro said:


> Would this still be the case with a Cerges reactor (RO filter housing) and an in-line heater on the 207 outflow? Not sure how many gph of circulation these items would scrub off, but it seems like the 207 might be borderline on a 20 gallon tank with this setup and I wonder whether a 307 would be a better choice due to the added resistance?


Yes, anytime you add anything upstream from the pump output that holds a larger volume of water than volume inside the hose you will be creating back pressure that will cut pump output. Also every hard angle turn water has to go through will also slow output down. That type of reactor will probably cut around 10-15% of pump output. Inline heater won't be so bad as it is just slight increase on inside volume and no turns for water to make.


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## Deanna (Feb 15, 2017)

Mostro said:


> Would this still be the case with a Cerges reactor (RO filter housing) and an in-line heater on the 207 outflow? Not sure how many gph of circulation these items would scrub off, but it seems like the 207 might be borderline on a 20 gallon tank with this setup and I wonder whether a 307 would be a better choice due to the added resistance?


Too many posters to cite individually, but I am doing much of what other posters recommend.

I put a 307 on my 29 gallon, knowing it was too much for my UVS and Griggs reactor (blows too many bubbles out) and this may happen with your Cerges and the 207. So, I put the “Y” in the output with a ball valve on the secondary output. The UVS and the Griggs are on the primary output.

I use the ball valve on the secondary output, rather than the throttle control on the filter, because the throttle control needs to be shut off with every filter cleaning and returning it to the desired flow position is difficult to judge (try to find 50% on their throttle control!). If I were you, I’d start with the one output and see if it provides enough flow, at greater than 50% of the rated output, without forcing too many bubbles through the reactor. If you reduce flow by more than 50%, it will burn out the motor faster. If it works, you’re done. If you get too many bubbles, then you can add the secondary output with the “Y” and valve.

I also substituted 5/8” tubing for the corrugated that comes with the filter, but you will have to use hose clamps because their screw-down clamps won’t fit over the 5/8” tubing.


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## Mostro (Aug 26, 2012)

DaveKS said:


> Yes, anytime you add anything upstream from the pump output that holds a larger volume of water than volume inside the hose you will be creating back pressure that will cut pump output. Also every hard angle turn water has to go through will also slow output down. That type of reactor will probably cut around 10-15% of pump output. Inline heater won't be so bad as it is just slight increase on inside volume and no turns for water to make.


So are you saying that yes, with roughly 5x turnover (10-15% reduction in gph from cerges reactor and in-line heater) the 207 is a good fit, or that yes, the 207 is marginal and the 307 (obviously would need to be throttled back) is a better fit? I guess that depends on what kind of tank flow is desirable. But I'm starting to think that sourcing a filter which flows the bare minimum may not be the best strategy out of the gate. Too bad there isn't a 207 point five.


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## butchblack (Oct 25, 2019)

jdwebb1 said:


> I see the hose size is 14.5mm, inside diameter I assume, which makes it hard to find a clear vinyl hose to replace it. The intake and output fittings are very displeasing to look at and will be difficult to hide among the plants. I can't even find glass lily pipes that will fit. Shame on Fluval if this is the case, I should have done more research I guess.


14.5mm id = 5/8" id tubing, Home Depot etc carries it. get some small hose clamps as the built in clamps on filters aren't always the best and sometimes the od of the tubing is larger than the tubing that comes with the filter. I always do that as Eheims are noted for not clamping non-Eheim tubing well


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## Quint (Mar 24, 2019)

If you get the acrylic tubing 5/8"ID 7/8"OD it will fit with the installed pressure fittings just make sure it is a good clean square cut on the tubing. When I went with a more flexible black tygon tubing I had to bevel the outside edge of the cut to get the pressure fittings to work. The softer tygon just didnt want to ride up under the pressure fitting lock but I got it to work.


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## DaveKS (Apr 2, 2019)

Mostro said:


> So are you saying that yes, with roughly 5x turnover (10-15% reduction in gph from cerges reactor and in-line heater) the 207 is a good fit, or that yes, the 207 is marginal and the 307 (obviously would need to be throttled back) is a better fit? I guess that depends on what kind of tank flow is desirable. But I'm starting to think that sourcing a filter which flows the bare minimum may not be the best strategy out of the gate. Too bad there isn't a 207 point five.


Heater it won’t matter much but on reactor as @Deanna pointed out you need a specific flow range for optimal efficiency. To little you won’t get proper dissolution, to much and, as was pointed out, you’ll get bubbles blown back into tank.

My comment was a general rule about flow dynamics when you start inserting vessels of larger internal size and extra turns in water path between pump output and tank nozzle. It was not about matching a certain size pump to a specific device. 

You need to do your homework and find recommended flow rate for your your reactor and meet or exceed that, you can always valve back and/or put reactor on its own loop. But if pump is under powered really no way you can correct that.


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## Deanna (Feb 15, 2017)

DaveKS said:


> Heater it won’t matter much but on reactor as @Deanna pointed out you need a specific flow range for optimal efficiency. To little you won’t get proper dissolution, to much and, as was pointed out, you’ll get bubbles blown back into tank.
> 
> My comment was a general rule about flow dynamics when you start inserting vessels of larger internal size and extra turns in water path between pump output and tank nozzle. It was not about matching a certain size pump to a specific device.
> 
> You need to do your homework and find recommended flow rate for your your reactor and meet or exceed that, you can always valve back and/or put reactor on its own loop. But if pump is under powered really no way you can correct that.


Too bad there aren't any *reliable* inexpensive, in-line, flow meters that could be placed just before the return to the tank.


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## Mostro (Aug 26, 2012)

DaveKS said:


> You need to do your homework and find recommended flow rate for your your reactor and meet or exceed that, you can always valve back and/or put reactor on its own loop. But if pump is under powered really no way you can correct that.





Deanna said:


> I put a 307 on my 29 gallon, knowing it was too much for my UVS and Griggs reactor (blows too many bubbles out) and this may happen with your Cerges and the 207. So, I put the “Y” in the output with a ball valve on the secondary output. The UVS and the Griggs are on the primary output.


The optimal flow rate for the "standard" Cerges reactor appears to be 120-150 gph, so I'll plan for a 307 on this 20 gallon knowing that I'll have to throttle it back and if necessary implement a secondary output as Deanna suggested.


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## joemomma (Oct 12, 2006)

Deanna said:


> Too many posters to cite individually, but I am doing much of what other posters recommend.
> 
> I put a 307 on my 29 gallon, knowing it was too much for my UVS and Griggs reactor (blows too many bubbles out) and this may happen with your Cerges and the 207. So, I put the “Y” in the output with a ball valve on the secondary output. The UVS and the Griggs are on the primary output.
> 
> ...


Do you think the 307 would be too much for a regular 29g that won't have the other attachments mentioned? I've always been a fan of buying slightly "more than you need" with filtration.


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## Quint (Mar 24, 2019)

Imho the 207 would be fine for a 29 but sure others will have other opinions.


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## YTP (Aug 26, 2019)

I have a 307 on my 29G with Jardli lily pipe and intake. I run it slightly less than full flow with no issues and gentle flow throughout the tank.


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## joemomma (Oct 12, 2006)

Thanks. I'm sure either will work fine.


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## Deanna (Feb 15, 2017)

joemomma said:


> Do you think the 307 would be too much for a regular 29g that won't have the other attachments mentioned? I've always been a fan of buying slightly "more than you need" with filtration.


Sorry; haven't been on for a while. 

For my 29 gallon, the Fluval 307 has to push through a UVS and a Griggs reactor. Total path, through the UVS, Griggs and 5/8" ID tubing (no corrugated), is about 6 feet. Rated output is 300 GPH. I measure actual at 180 GPH.

My guess is that you might get actual 250 GPH with none of my attachments and half the path length. However, if you use their corrugated tubing that came with the filter, you might see that reduced by about 15%.


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## joemomma (Oct 12, 2006)

Ended up picking up a 306 for a good deal from one of the large chain stores....they had a $30 off $100 purchase and free shipping. We have a store here locally, but I won't need it for several more days. I'm still building the stand.


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