Co2 And Bubble Counting

[aaronc]

Hey All

I have just got my pressurised CO2 and have set it up as per the manual

I am trying to get the system running at 10 bubbles per minute as a starting point.

This is fine in principal - I stick the tube in a glass of water and adjust the needle valve - voila.

However when I add the diffusor to the system - no bubbles come out of it.

Is this something to do with the pressure created by the diffusor.

So my question is - do I need to recount with the diffusor in place and use this rate?

Cheers
Aaron

 

[SuperColey1]

You need a bubble counter. This will fit inline and then you see the bubbles pass through the water into it. thr 'bubble count' on a diffusor is totally different.

For example at the mo my bubble counter is going at 3 bubbles per second yet only 1 bubble every 5 seconds go into the diffusor!!! quite different readings. Always dependant on the bubble counter/diffusor you are using because a bubble in one can be a tottally different size to anothers. This is why we use drop checkers to see where we are at and not the bubble counter.

If you have a drop checker I would set it so your diffusor (Rhinox2k or similar) is receiving approx 1 bubble every 10 secs and then watch your drop checker to see where you are remembering it will always be a few hours behind the actual level.

I hope you have a non return valve somewhere on the line? don't want the water to return into the regulator as it knackers it.

Andy

 

[aaronc]

Hey

I have a check valve. I will set the level and then add the diffusor

One over question - why would my operating pressure drop to 0? A leak somewhere?

Thanks
Aaron

 

[SuperColey1]

either that or the cannister is empty / regulator not open. the outflow gauge should read whatever you turn it to even if there is no hose attached.

You can't set the level and then connect to the diffusor. As you asked earlier yes there is a connection between the diffusor being there as it creates some backward pressure within the hose. If I remove my diffusor whilst the CO2 is turned on then the bubble counter goes up significantly to what it is when connected. This is probably the same reading but the bubbles maybe smaller due to the speed they can then escape!!

Andy

 

[aaronc]

Ok cool

I have ordered a bubble counter from AE.

The pressure was a 1 earlier - have just come back from the cinema and it was back at 0 - although it might have been that I hadnt set it properly and it slowly dropping as the co2 was used or something. Not too sure - will monitor it.

I have the permanent CO2 test in there for the moment so will adjust it accordingly.

Cheers
Aaron

 

[aaronc]

Edit - I have just hooked up the old pop bottle bubble counter from my DIY yeast setup to get some idea of a bubble count for the ineterim

 

[SuperColey1]

pop bottle should be OK

When you first turn it on (everything connected and ready, diffusor in tank and all) it will look like it is going mad.

This will be until it settles on a pressure, after which it will lsettle down and give you a true reading so let it blast away for 5 minutes or so before you start to adjust the levels.

Andy

 

[aaronc]

Ahh right - that might be why I need to tweak the operating pressure for a while.

Out of interest what size is your tank. Would be interested to know what bubble counts people operate at - i know this is very much dependent on tank, and planting levels, surface agitation etc. The dennerle manual says 10 bubbles a minute for a 100litre tank.

Seems very very low

Aaron

 

[SuperColey1]

I would treat any manufacturers guides as a starting point really. They tend to err on the low side so they can say their bottles last ages. lol

Factors as you say are:

Plantmass
Lighting
diffusor efficiency
circulation
surface agitation
Tank size etc.

My tank is 125Ltr but someone else's 125Ltr with the exact same plants but more lighting would obviously use more CO2.

I run at 2bps with fish but at the moment I have noe so am powering the CO2 in at 3-4bps with 1400lph of filtering!!! providing the current.

Andy

 

[Wolfenrook]

Ok cool

I have ordered a bubble counter from AE.

The pressure was a 1 earlier - have just come back from the cinema and it was back at 0 - although it might have been that I hadnt set it properly and it slowly dropping as the co2 was used or something. Not too sure - will monitor it.

I have the permanent CO2 test in there for the moment so will adjust it accordingly.

Cheers
Aaron

Sounds to me like you have a leak possibly, you might want to check.

Don't get too caught up in bubble counting, it isn't the most accurate way of guaging CO2 but rather a rough guide. Different kit has different bubble sizes. Better to use that as a basic guide, and combine this with the colour in your permanent test (if you haven't already replace the tank water in this with some pure water with the KH buffered to 4 degrees, if you live in the UK or europe aquaessentials sell this ready made).

No bubble counter anywhere on my kit, I count the bubbles as the gas enters my diffuser (rhinox style pollen glass).

Ade

 

[aaronc]

Hey

I only want the bubble counter as a starting pointer - so I dont gas my fish

I have a permanent test in there already and 4DKH water from AE

Cheers
Aaron

 

[aaronc]

Grrr bubble counter arrived and leaks lol