Number of diffusor

tim85

Junior Poster
Feb 7, 2009
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I have noticed from postings here that many have huge tank like 180g. I too am thinking of getting one that size.

I have read that Tom suggested 2 diffusors to be used for 120g. I know that Gerryd is using Mazzei. And I also have read that Tom switched back to diffusor for his 180g. Tom, are you using 2x diffusors in your 180g?

I am really hoping that those that have 120g and above would tell us they method of introducing CO2 into their tank, ie 1 diffusor or 2x diffusors or 2x reactors or Mazzei or perhaps 1x diffusor together with a reactor.

TIA.
 

Tom Barr

Founder
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Jan 23, 2005
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Yes, larger tanks require multiple diffusers disc.

They can only handle so much flow rate through the plate.
So even the larger 5 cm plates can only handle so much without going to larger bubble sizing and producing less fine mist over time. The other issue is that the CO2 tubing will bust off due to excess back pressure if the flow rate is too high.

With 2 or more, you get a few more options for spreading it out, this can be good or/and bad depending on the view and position of the diffuser, layout, scape etc.

Regards,
Tom Barr
 

rthomas

Guru Class Expert
Oct 25, 2007
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I generally do agree with Tom's suggestion. That said, I am still using a single diffusor in my 180g :p

Actually it depends on the scape, I think. My setup is an Iwagumi. I don't have thick and bushy jungle in my tank. Most are HC and a few Crypts. So with a single diffusor placed underneath a Koralia 4, I can see that all the tiny bubbles were sent to all corners of my tank. I have rev up the bubble count, but to a level that can be handled by the diffusor and CO2 tubing; like what Tom cautioned.

I also dose CaSO4 after every WC. This is another test that I use to look at the path of the water flow. I mixed CaSO4 in a beaker and pour it in front of my Koralia, then watch the flow path. Even without watching my tiny CO2 bubbles, I know that my CO2 reached all corners.

That said, mine is an Iwagumi setup. But if your setup consisted of thick and bushy jungle, I strongly suggest that you go with 2x diffusors.
 

Tom Barr

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Jan 23, 2005
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You can only add so much CO2 through a single set area, and as you increase that, you also increase pressure. While you can push more through the diffuser, it loses efficiency as bubble sizes increase, pressure increases etc and you can easily pop off the CO2 gas line holding the tube on the reactor(Eg ADA, Rhinox etc)

You cannot just simply forever increase the gas flow in other words.
They have max rate limits, and for larger tanks, IMO and IME, having 2 or more is wiser for 4-6ft tanks. The open scape with lower light at Aqua forest uses one diffuser I think:

180cm26th.jpg


I recall more though. I'll have to look.

Regards,
Tom barr
 

rthomas

Guru Class Expert
Oct 25, 2007
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Great pix there Tom. Think I have seen that before BUT it's the kind of tank tank most of us (at least) me dream of. What's the spec btw? Are those pendant MH ?