• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up
  • You can now follow UKAPS on Instagram.

Increase C02 Ciculation

Jasonm

New Member
Joined
28 Dec 2021
Messages
13
Location
Walsall
Hello all.
Can anyone advise on a way to increase circulation of C02, i have a Fluval Shaker which is a high tank, diffuser is setup bottom left, i get a lot of concentration of bubbles at the middle high centre but no matter how i position the returns i'm struggling to push them down to the bottom. Its my 1st pressurised setup so any help would be great

20211228_222535.jpg
 

Jasonm

New Member
Thread starter
Joined
28 Dec 2021
Messages
13
Location
Walsall
Its 168l, ive looked briefly at inline diffusers and was trying to find something that showed how to connect to the Fluval cannister filters as i think the standard pipework would need changing to accomadate.
 

John q

Member
Joined
6 Jan 2021
Messages
1,222
Location
Lancashire
Hi Jason, to go inline you'd probably need to switch out those ribbed hoses for standard 16/22 hoses.

One thing you could try is getting a smaller diffuser and place it next to the inlet in the tank. Like this.
20211230_143814.jpg
20211230_143727.jpg


This works for some and I'd suggest it will be better than the set up you currently have.

Just on a note of caution you might need to reduce the amount of gas that's coming out of the new diffuser.

Cheers.
 

Jasonm

New Member
Thread starter
Joined
28 Dec 2021
Messages
13
Location
Walsall
Hi Jason, to go inline you'd probably need to switch out those ribbed hoses for standard 16/22 hoses.

One thing you could try is getting a smaller diffuser and place it next to the inlet in the tank. Like this.
View attachment 179106View attachment 179107

This works for some and I'd suggest it will be better than the set up you currently have.

Just on a note of caution you might need to reduce the amount of gas that's coming out of the new diffuser.

Cheers.
Thanks John, i didn't think you could place it near the intake, just looked at posts of people using this method and it looks like it works for a lot of them, i'll give it a try
 

John q

Member
Joined
6 Jan 2021
Messages
1,222
Location
Lancashire
No worries mate.

Truth is its difficult getting good distribution around these deep fluval tanks, especially with the twin duckbill outlet. One thing that might help is not to have your filter rammed with media, this will ultimately reduce the output from said filter.

I'm assuming you have the fluval 307 filter, this should handle the gas being feed into the inlet, providing you're not pumping ridiculous amounts through it. You may find it burps out some bubbles on occasion, for some people this can be annoying.
 

Jasonm

New Member
Thread starter
Joined
28 Dec 2021
Messages
13
Location
Walsall
Its the 207 that comes with the 168l, i have changed the media about in the trays, the bottom still has the large sponge but the top two trays have biohome media,im not too bothered about it shooting some bubbles out now and again, am i looking to send all the bubbles straight into the intake..? i'm going to try and use the diffuser i have at first its the small bazooka,
 

John q

Member
Joined
6 Jan 2021
Messages
1,222
Location
Lancashire
i'm going to try and use the diffuser i have at first its the small bazooka,
You can probably use a rubber band to attach the bazooka verticaly to the inlet cage or partially bellow it, experiment and see which position gets the most bubbles into the inlet.

Its the 207 that comes with the 168l, i

I've a feeling you might need to get a bigger filter at some point to get decent flow around this tank. The general guidance is 10x tank turnover and whilst this isn't always required i think you'd only be getting 4.5x turnover with the 207. Other option would be to get a small wavemaker or circulation pump in the tank.

See how it goes placing the diffuser on the intake for now before rushing out and buying more kit.
 

Jasonm

New Member
Thread starter
Joined
28 Dec 2021
Messages
13
Location
Walsall
've a feeling you might need to get a bigger filter at some point to get decent flow around this tank. The general guidance is 10x tank turnover and whilst this isn't always required i think you'd only be getting 4.5x turnover with the 207. Other option would be to get a small wavemaker or circulation pump in the tank.
Not a problem getting a bigger cannister if needed, would the 407 be too much..? you would think the kit supplied would be adequate
 

Nick potts

Member
Joined
25 Sep 2014
Messages
956
Location
Torbay
Not a problem getting a bigger cannister if needed, would the 407 be too much..? you would think the kit supplied would be adequate
407 would be fine. Often (i would say always) with these kit tanks the filter is under specced.

The filter inlet is worth a try, it doesn't always work but costs nothing to try, failing that I would be adding an extra powerhead for flow and to move the co2 around.

Also, i wouldn't be running the airstone while co2 is on, it will be off-gassing a lot of what you are injecting, if you can i would have it on a timer to come on when lights go off.
 

John q

Member
Joined
6 Jan 2021
Messages
1,222
Location
Lancashire
you would think the kit supplied would be adequate
If you were just keeping fish (not heavily stocked) in the aquarium or going the low tech route then the supplied filter would probably be ok.

I would imagine a 407 in a tank that size would be adequate that should give you 8.6x turnover.
 

Jasonm

New Member
Thread starter
Joined
28 Dec 2021
Messages
13
Location
Walsall
Would anyone recommend the OASE cannisters..? i like the idea that the heater is built in and not visible in the tank, would the 850 be too much..?
 

Nick potts

Member
Joined
25 Sep 2014
Messages
956
Location
Torbay
Would anyone recommend the OASE cannisters..? i like the idea that the heater is built in and not visible in the tank, would the 850 be too much..?
I don't use them but they get good reviews on here and in most places.

The 850 IMO would be fine, always take the stated flow advertised with a pinch of salt, most would recommend halving it for the real flow it would output
 

jaypeecee

Member
Joined
21 Jan 2015
Messages
2,680
Location
Bracknell
Otherwise you're asking the filter to do something it really isn't particularly good at.
Hi @Jasonm

I completely agree with what @Andy Pierce has said above. I have had a lot of success using what's known as a streaming pump. I like the product shown below:


And, they are very reasonably priced.

I positioned mine on the aquarium glass several centimetres above the CO2 diffuser. That way, the CO2 microbubbles get sucked into the streaming pump and blown wherever you direct the flow.

Whatever you choose, I advise that it has flow control - otherwise your plants will think that monsoon season has arrived!

JPC
 

John q

Member
Joined
6 Jan 2021
Messages
1,222
Location
Lancashire
Hi @John q

I have heard of instances where the CO2 can get trapped in the filter and get very noisy.

JPC
Yes I believe this can happen with some filters. The fluvals seem to handle having co2 put through them without causing any extra noise, you do get an occasional build up of gas which gets burped out, for me this happens about once an hour or so.

I suppose it all depends on how much gas gets drawn into the filter.
I run 2 diffusers in the tank and would say 40% of the co2 is sent to the inlet diffuser, which probably equates to about 4bs.

The logic for my tank would be to go inline.

Unfortunately we had a major flood in the house in May (non fish tank related) and it caused an incredible amount of damage, I worry now (or rather my Mr's does) about putting another point of failure into the system so have to put up with in tank diffusers.

The illogical part is I build pressure vessels for a living that carry hazardous chemicals at around 4 bar pressure, and yet baulk at the idea of splicing a piece of 22mm tube.
 
Last edited:

Jasonm

New Member
Thread starter
Joined
28 Dec 2021
Messages
13
Location
Walsall
I've purchased an inline diffuser from C02 Art, hoping that the additional flow from the upgrade to the 407 will push it around the tank better, my only concern though will be the maintenance of it and as John has mentioned another failure point, inlet and outlet on the shaker are directly underneath the tank which i suppose is a high risk in itself anyway, if i put 16/22 Eheim valves either side this would increase the risk also, i like the idea of a powerhead but want to stray from adding additional items to the tank as its not too wide and would start to look clustered.
 
Top