# what to do with venturi hole of powerhead?



## qpixo (Sep 9, 2006)

I'm using a powerhead using a gravel tube to inject co2 in my 10gal tank.
What to do with a powerhead venturi hole?
For now on, I just stick the tube which comes from the brand in that hole. Last night, when I turned my powerhead off, I got water drowning out off my floor. 
I'm wonderring how to prevent that mess?

Assuming plants don't need co2 at night...


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## jamesB (Aug 31, 2006)

I am a bit confused on how you are getting co2 to the power head if you are not using the venturi hole. However, if you are not using the hose to push anything down to the venturi hole then you should just cap the hole; don't run a hose out of the tank. If you are using the hose to supply gas to the venturi system put a check value on the line to keep water from siphoning through the hose.


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## schaadrak (Aug 18, 2006)

The tube goes from the venturi hole back into the side of the gravel tube, through a hole drilled in the side.

Like in this thread: Barr Internal Venturi CO2 Reactor


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## qpixo (Sep 9, 2006)

malbe I was'nt clear about what I've said. 
I did the same design as DIY CO2 System for Planted Aquarium
to supply CO2 in my tank.

I got some water drowning out while I turned my powerhead off I guess it was due to the siphon and I'd like to know is what I have to do with that venturi hole????


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## Chris S (Feb 27, 2006)

do you have the CO2 bubbling into the impeller? I covered my venturi hole and simply closed it off. I found when I was running this type of reactor that there was no real reason to be using the venuri hole for this application. The bubbles where smaller when i ran the CO2 into the impeller rather than the actual venturi hole.


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## schaadrak (Aug 18, 2006)

qpixo said:


> malbe I was'nt clear about what I've said.
> I did the same design as DIY CO2 System for Planted Aquarium
> to supply CO2 in my tank.
> 
> I got some water drowning out while I turned my powerhead off I guess it was due to the siphon and I'd like to know is what I have to do with that venturi hole????


That is the same powerhead reactor, the difference is the venturi tube goes into the reactor chamber so that when the CO2 bubble gets to big, it gets fed into the powerhead stream to help break it up.


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## qpixo (Sep 9, 2006)

How do you cover up the venturi hole? with what kind of stuff?
I'm using their tube and venturi valve to cover right now. But somehow when I turn the powerhead off, it creates some kind of siphon and water sucks up easily.

do u actually turn your powerhead down at night?



Chris S said:


> do you have the CO2 bubbling into the impeller? I covered my venturi hole and simply closed it off.


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## Chris S (Feb 27, 2006)

qpixo said:


> How do you cover up the venturi hole? with what kind of stuff?
> I'm using their tube and venturi valve to cover right now. But somehow when I turn the powerhead off, it creates some kind of siphon and water sucks up easily.
> 
> do u actually turn your powerhead down at night?


 I inserted an airline tubing in the venturi hole. Then, I installed a valve that came with my powerhead which is designed to control the flow rate of air into the venturi. I simply closed the valve all the way so it could not suck any air or siphon out any water from the tank. The reason that i did this is that with my particluar power head design and internal reactor "Barr Style", the venturi acted in reverse and was under presssure. I was losing CO2 mist out of the top of the venturi hole and it no longer was taking in any suction. Since then in my 20 gallon i have no internal reactor and use only a CO2 powerhead mist in that tank with good results and less hardware.


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## Chris S (Feb 27, 2006)

p.s. notice that the power head in the above link(diagram) has no venturi hole.


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## qpixo (Sep 9, 2006)

this is what I'm using too but I think my airline is a bit too long. So I cut it not reach out my tank, that way water won't come out even if it has been sucked up any air/siphon.

What's the internal reactor "Barr Style" needs to do in a tank?? If you already have a co2 powerhead? I don't get that though...



Chris S said:


> I inserted an airline tubing in the venturi hole. Then, I installed a valve that came with my powerhead which is designed to control the flow rate of air into the venturi. I simply closed the valve all the way so it could not suck any air or siphon out any water from the tank. The reason that i did this is that with my particluar power head design and internal reactor "Barr Style", the venturi acted in reverse and was under presssure. I was losing CO2 mist out of the top of the venturi hole and it no longer was taking in any suction. hardware.


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## Chris S (Feb 27, 2006)

I used to use one of these http://www.aquaticplantcentral.com/...al-venturi-co2-reactor.html?highlight=venturi
now i only use the power head aimed low and got rid of the gravel tube.


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