# JBL Spiral Diffuser



## andyniceday (9 Jan 2010)

Hi,

Im using a JBL spiral diffuser with my DIY yeast setup, im getting plenty of bubbles from the setup but im concerned about how much of it is actually diffusing into the water.

The bubbles do shrink in size as they go up the spiral, but im left with perhaps pea-sized bubbles at the top which just build up and eventually pop out of the top of the diffuser and to the water surface. Id say only 1/4 of the bubble that comes out of the pipe is actually diffused into the water. 

Droper checker indicates good co2 levels all round the tank, but is it this normal with any setup to see so much waste co2 escaping? Would an alternative diffuser help make things more efficient?

Thanks!


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## gratts (9 Jan 2010)

Hi Andy.
I've used the JBL Spiral in a few tanks and found them to be quite poor overall. In my experience they benefit from a good flow running past the diffuser to remove the CO2 enriched water, but even then the overall dissolution rate is quite low compared to others. I've recently switched to a different diffuser:
http://cgi.ebay.co.uk/CO2-Carbon-Dioxid ... 1c0eb102df

And am experiencing much better levels of CO2 and a decrease in the amount I'm having to pump into the tank, which leads to much happier plants! Long term I really would look at changing. It's hardly a large outlay of money and you'll save it in gas cost in the long run


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## Dolly Sprint 16v (10 Jan 2010)

andyniceday said:
			
		

> Hi,
> 
> Im using a JBL spiral diffuser with my DIY yeast setup, im getting plenty of bubbles from the setup but im concerned about how much of it is actually diffusing into the water.
> 
> ...



Andy
My very first kit was a dennerle which used a ladder system as the attached you tube video:
http://www.youtube.com/watch?v=HWSy32Sq ... re=related - when i first installed the system pea size bubbles where at the bottom of the ladder and as they progressed up the ladder the remained the same size, the following day the bubbles where gradually decreasing in their size as they travelled up the ladder and by the time they reached the top the bubbles were slightly bigger than a pin head, Dennerle stated within there manual that it would take 24 hours to settle down - this was true . Over the following months I had to increase my supply of co2 into the tank and I found that due to the quantity of bubbles being injected the ladder system was not diffusing the gas enough as the bubbles were not decreasing in their size - so I slowed the injection bubble rate down and sure enough the bubbles travelling up the ladder decreased in the size. This told me that the ladder was not long enough.
A nothing clip showing a large bubble at the bottom which decreases in its size as iy travels up the ladder;
http://www.youtube.com/watch?v=ATDvXXOX ... re=related.
You JBL spiral ladder works on the same prinicple - large bubble at the bottom and as it spirals up the tube the bubbles should get smaller. So I would say that you are injecting the gas to quick and it not having enough time to within the water - slow your injection bubble rate down or lenghten the spiral - you can purchase entension kits.

I have some spare extension kit - send me a pm and we can come to some arrangement.

Regards
paul.


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