Co2 increase canister filter noise with low BPS

[eminor]

Hello, i have a tetra ex 1200 plus filter, i also have inline atomizer on the outlet of the filter, i have around 3 bps, drop slightly green, the noise of the filter has increased, sound like trapped bubble in the impeller chamber, is there a way to fix that ? thx

The co2 is really a fine mist so the diffuser seems to work perfectly

 

[Hanuman]

Are you sure it's the CO2 entering the filter that is generating this gas pocket/noise or is it perhaps that the filter is not sealed properly and allows air inside the canister? If it's the former then I guess there isn't much you can do about it other than perhaps using a CO2 reactor to avoid having CO2 in gaseous form in the water column.
As a starter, I would be you I would open the filter and add some silicone grease to all o-rings and sealing rubbers to discard the possibility of sucked air being the reason. I do this even to new and never used filters. I even do this once I retire the filter when I upgrade filters to make sure the rubbers don't hardened and crack. You never know when you might need to re-use the filter again for whatever reason. If you are sure it's not some air, then my friend, the only way would be a reactor.

 

[erwin123]

Can you confirm that its related to the CO2. Meaning that when CO2 has been off for several hours, the filter is silent?
If that's correct, then it suggests that you have way too much undissolved CO2 in your water.
I place a CO2 diffuser at 1bps at the inlet of my Fluval 307 and I get no gas pocket sound or CO2 'burping' from my canister.

 

[Hanuman]

If that's correct, then it suggests that you have way too much undissolved CO2 in your water.

3 bubbles per second is not really that much. I've had much more than that when I was using inline and in-tank diffusers and I didn't have canister noises related to CO2 being trapped. Only thing I could think of is that CO2 is not off-gassing efficiently and then gazeous CO2 builds up in the water column as you said.

I place a CO2 diffuser at 1bps at the inlet of my Fluval 307 and I get no gas pocket sound or CO2 'burping' from my canister.

I think that's really dependent on the canister model/brand and internal design. Some are more prone to traping gases than others. Some have air release mechanisms designed within the impeller housing assembly which prevent large pockets of air being trapped and instead release progressively any gas getting in.

 

[LightingBamboozled]

First thing to check is, is your filter level? The EX-1200 can purge small amounts of air but only if it's pretty close to level.

Air build up in the Tetra EX series I usually find to be an intake issue. Hav you double checked the connections around the U Bend to make sure they're not drawing air? (Also make sure the intake and outlet pipes are fully open)

If that's not happening then as Hanuman says the next culprit might be the O-rings. Check for phyical dirt or damage on the O-rings. Make sure they're seated correctly, potentially grease them although that shouldn't usually be necessary. Make sure the lid of the cannister is closing correctly, you shouldn't have to force any of the 4 catches. (At this point it behooves me to ask which version of the Tetra EX1200 head you have. Do you have 4 long clips attached to the filter body or two long clips on the body and two short clips on the pump head?)

If yourfilter is level, intake is airtight and your cannister is properly sealed then can you see bubbles entering your intake in the tank? If lots of CO2 is making it to the filter intake then it may be the case that you need to reduce your bubbles or adjust your flow.

 

[eminor]

Are you sure it's the CO2 entering the filter that is generating this gas pocket/noise or is it perhaps that the filter is not sealed properly and allows air inside the canister? If it's the former then I guess there isn't much you can do about it other than perhaps using a CO2 reactor to avoid having CO2 in gaseous form in the water column.
As a starter, I would be you I would open the filter and add some silicone grease to all o-rings and sealing rubbers to discard the possibility of sucked air being the reason. I do this even to new and never used filters. I even do this once I retire the filter when I upgrade filters to make sure the rubbers don't hardened and crack. You never know when you might need to re-use the filter again for whatever reason. If you are sure it's not some air, then my friend, the only way would be a reactor.

When i used lower bps, the filter was dead silent, once in increased it, i heard some rattling sound, when i bought the filter i removed every o-ring to lub them

Can you confirm that its related to the CO2. Meaning that when CO2 has been off for several hours, the filter is silent?
If that's correct, then it suggests that you have way too much undissolved CO2 in your water.
I place a CO2 diffuser at 1bps at the inlet of my Fluval 307 and I get no gas pocket sound or CO2 'burping' from my canister.

Well, it take more than hours, if i slow the bps, it takes a day or two then the filter get silent. I don't know how it cant disolve, the bubble are so tiny, a mist. i have no problem with @1bps neither but too low co2

3 bubbles per second is not really that much. I've had much more than that when I was using inline and in-tank diffusers and I didn't have canister noises related to CO2 being trapped. Only thing I could think of is that CO2 is not off-gassing efficiently and then gazeous CO2 builds up in the water column as you said.

I think that's really dependent on the canister model/brand and internal design. Some are more prone to traping gases than others. Some have air release mechanisms designed within the impeller housing assembly which prevent large pockets of air being trapped and instead release progressively any gas getting in.

So if i increase the gazeous exchange, the noise could stop ?

First thing to check is, is your filter level? The EX-1200 can purge small amounts of air but only if it's pretty close to level.

Air build up in the Tetra EX series I usually find to be an intake issue. Hav you double checked the connections around the U Bend to make sure they're not drawing air? (Also make sure the intake and outlet pipes are fully open)

If that's not happening then as Hanuman says the next culprit might be the O-rings. Check for phyical dirt or damage on the O-rings. Make sure they're seated correctly, potentially grease them although that shouldn't usually be necessary. Make sure the lid of the cannister is closing correctly, you shouldn't have to force any of the 4 catches. (At this point it behooves me to ask which version of the Tetra EX1200 head you have. Do you have 4 long clips attached to the filter body or two long clips on the body and two short clips on the pump head?)

If yourfilter is level, intake is airtight and your cannister is properly sealed then can you see bubbles entering your intake in the tank? If lots of CO2 is making it to the filter intake then it may be the case that you need to reduce your bubbles or adjust your flow.

Filter is level, the filter is closed perfectly, there is 2 clips on the head and 2 on the body yes, i don't have to force them, everything is near perfect to be honest

Co2 is a mist so there might be some entering the intake for sure

 

[Hanuman]

So if i increase the gazeous exchange, the noise could stop ?

If you do that more CO2 will off-gas reducing the amount of CO2 that goes into the canister, so potentially reducing noise. This said I doubt it will be enough to completely remove the noise. It looks to me that your canister poorly manages gases that get into the head. Only way I see in resolving this is by using a CO2 reactor or injecting less CO2.

 

[LightingBamboozled]

there is 2 clips on the head and 2 on the body yes, i don't have to force them, everything is near perfect to be honest

Ah, that's the old style head. It was less efficient at purging air (and slightly more prone to leaks) than the new head. Short term solution. Tip the filter back, towards the hoses, about 5-10 degrees, hold it there for 5 seconds, then rapidly return it to vertical. This should remove the bubble built up in the top of the filter if done once or twice. But it won't stop it building up again in the future.

When you look at the intake hose on the filter are there any bubbles visibly going into the filter (To spot this i find it helps to shine a light through the hose at 90 degrees to the angle I'm looking at).

Could we get a photo of your intake to see how much CO2 there is bubbling around it?

 

[eminor]

Ah, that's the old style head. It was less efficient at purging air (and slightly more prone to leaks) than the new head. Short term solution. Tip the filter back, towards the hoses, about 5-10 degrees, hold it there for 5 seconds, then rapidly return it to vertical. This should remove the bubble built up in the top of the filter if done once or twice. But it won't stop it building up again in the future.

When you look at the intake hose on the filter are there any bubbles visibly going into the filter (To spot this i find it helps to shine a light through the hose at 90 degrees to the angle I'm looking at).

Could we get a photo of your intake to see how much CO2 there is bubbling around it?

here's a little video, dont know if the quality is good enough, doubt lots of mist enter in, the filter do not burple though, just the rattling noise

 

[LightingBamboozled]

Yeah with that level of mist you shouldn't be getting CO2 build up into the filter. And there's no obvious gas flowing down into the filter in that green hose down the back (that I presume goes to the EX1200Plus).

If it's ratting it might not be gas. When did you last clean the impellor and rotor? Grit in there rattles like billy-o.

 

[hypnogogia]

here's a little video, dont know if the quality is good enough, doubt lots of mist enter in, the filter do not burple though, just the rattling noise

I can’t hear a thing - possibly no sound on the video?

 

[eminor]

Yeah with that level of mist you shouldn't be getting CO2 build up into the filter. And there's no obvious gas flowing down into the filter in that green hose down the back (that I presume goes to the EX1200Plus).

If it's ratting it might not be gas. When did you last clean the impellor and rotor? Grit in there rattles like billy-o.

two month ago i cleaned the impeller and used silicon grease, it was the most silent filter i ever had. The impeller was still clean 2 weeks ago though ( i did not removed it though)

I can’t hear a thing - possibly no sound on the video?

here's the sound of the filter, sorry for the moving camera i was trying to activate the led...

video

 

[eminor]

Update : it was one of the basket that was not well in place