# Advice on D-D CO2 Set



## mike_low3 (20 May 2009)

Hi There
I'm looking for some advice on wether the D-D CO2 sets are any good, it's hard to tell from the pictures you see on retailers sites if the equipment is any good, just wanted to know how easy the setup was and if anyone has any advice on the diffuser that comes with the set, is it worth keeping or do most people replace it with something better.

I've almost made my mind up to buy one, but I'm also thinking can I use my eheim external return/spraybar to disperse the CO2 ?
Thanks
Mike


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## chris1004 (21 May 2009)

I have used one of these for the last year or so and have got along with it fine, (hope thats not tempting fate) I did have a small leak on one of the joins once but it isn't difficult to fix just dismantle and reassemble using a generous ammount of ptfe tape applied to the threads. You should always check the joins whenever you replace a co2 bottle whatever the make of regulator set used it doesn't take long just brush soapy water onto all of the joins and if there is a leak its blatently obvious as it produces bubbles. 

If you get there adapter you can easily fit it to a fire extinguisher (mine is) for much cheaper co2 running costs. The supplied co2 diffuser/bubble counter is ok but basic and before I replaced mine with an external diffuser it worked fine, a little difficult to initially half fill with water though, I had to use a syringe to force some into the chamber.

I have found the set easy to use and install but would highly recomend a drop checker be installed at the same time to measure how much co2 is disolved in the water (i made the mistake of not having one and suffered as a consequence) and be aware that getting the desired level isn't an exact science and fluctuates with many influencing factors like flow, plant  biomass and co2 canister pressure which are variables themselves influencing the results. Therefore its advisable to check and 'tweek' daily if necessary, getting a new co2 canister to settle down can also take a week or so but any additional co2 should be added in small increments so as to not stress and/or risk gassing your fish.

There are some very good articles in the tutoriol section of this website with regard to co2 and drop checkers and are highly recommended reading.


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## nry (21 May 2009)

After using one for about 18 months, the seal gave up on the regulator to the cannister...perhaps me over-tightening but unsure.  The bottles can be bought from Machine Mart for under Â£10 rather than the Â£17-Â£25 ones online to save some money, but to be truthful, I have just replaced it all with a Â£55 eBay dual-guage regulator, a Â£5 eBay Boyu external inline diffuser and a Â£24 2KG fire extinguisher.  Far more for noticeably less - unless the 500gm bottle is the largest you can accomodate then I'd not bother with the D-D set and go for something like I have now got.

My D-D set also came with a rio powerhead/CO2 mister and not a diffuser...no idea how standard this is as the item description did say a two-gauge regulator and diffuser...


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## mike_low3 (21 May 2009)

Thanks for the advice, I've more or less made my mind up on buying this set, and I'm also looking at buying a drop checker from aqua essentials, I'll wait and see what diffuser turns up with the kit, then make my mind up on wether to replace it with something better !
Thanks
Mike


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## chris1004 (21 May 2009)

nry said:
			
		

> After using one for about 18 months, the seal gave up on the regulator to the cannister...perhaps me over-tightening but unsure.



Correct me if I'm wrong but I'm sure that this is just a rubber washer and as such it should be really easy to source a new one, or have I got hold of the wrong end of the stick?

Co2 will perish rubber over time anyway (acid) and the advice that I received from my lfs when I first bought my regulator kit was to replace the rubber washer every other bottle as a matter of routine maintenance. Maybe I fell for his speil but he even sold me replacement washers to fit the FE adaptor there and then. Mind you at a quid for two he's laughing all the way to the bank, I will try to source these elsewhere cheaper when I get the time.


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## chris1004 (21 May 2009)

mike_low3 said:
			
		

> I'll wait and see what diffuser turns up with the kit, then make my mind up on wether to replace it with something better !
> Thanks
> Mike



The diffuser that I got with mine was this one:-

http://www.aquaessentials.co.uk/index.p ... ts_id=2162

Or it might have been the smaller version of the same model I can't quite remember now. Basically you half fill the diffuser up to the shoulder with water and it acts as a diffuser and bubble counter combined. A little tacky maybe but it works ok and is sufficeint to get you started.


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## nry (21 May 2009)

Due to the really awkward location of the washer (which is also shaped!) getting a correctly sized replacement is almost impossible.

For the money I really wouldn't buy one again, the same if not better can be done for about Â£50 less...and with a 2KG FE your money would go even further in the long run too.


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## mike_low3 (9 Jun 2009)

I went ahead and bought the D-D unit, I'm in the process of setting it up at the moment, it actually came with one of these diffuser/bubble counters

http://www.aquaessentials.co.uk/index.php?main_page=product_info&products_id=2162

Does anyone have any advice on how you fill it with water, and how much to add to it ?

Thanks
Mike


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## chris1004 (9 Jun 2009)

Yeah tricky isn't it!!

Not sure how you are supposed to do it but I just connected a short (1" apox) piece of air line to it and used a syringe to force water into the chamber. You only need to half fill it with water though filling it right up makes it less effective and it would probably be harder to get the water out than it is to get it in!!!!   

I don't personally think that you will regret buying the D-D regulator I know that others have differing opinions but thats life and is true for most things, mines ok, good luck with yours.


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## mike_low3 (10 Jun 2009)

Thanks for the reply, stupidly I managed to snap the tube connector...but hopefully a bit of glue will hold it in place, I'll try the tip with the small piece of air line and fill it half way, I'm going to give it a try tonight so fingers crossed.

I've read what others have said on the DD set but it seems a good piece of kit so fingers crossed it does the job.
Cheers
Mike


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## mike_low3 (18 Jun 2009)

Can I just check something regarding the use of regulators, the D&D manual states that after testing for leaks that I should reduce the pressure back to 1 barby fully tighening the course valve, which could only do by loosening the fine valve to release CO2, it then stays at 1 bar.

So what I've noticed is that when I want to relase CO2 into the tank I release the fine valve but nothing happens, so I have to start playing about with the course valve again and then the pressure changes, what am I doing wrong ?


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## chris1004 (19 Jun 2009)

If you think about it for a minute if you fully toghten the coarse valve then you are shutting off the supply completly so its not supprising that no co2 is being released really.

I run mine at about 1.5 bar which is set using the coarse valve once the solenoid valve is open and the needle valve is roughly in mid position. I then tweek the needle valve to get the required flow. If the output pressure rises or drops just re-adjust the coarse valve back to 1.5 bar on the pressure dial. Monitor the situation very closely when you first put a new canister on and when the canister is nearing empty as output pressures can fluctuate wildly at these times. It often takes a week or so to settle a new canister in.


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## mike_low3 (22 Jun 2009)

Thanks for that advice, I've set to 1 bar and adjusted the fine valve to give me about 1 bps, I'll keep monitoring the drop checker


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## chris1004 (22 Jun 2009)

I find it a little bit easier to keep things stable with a slightly higher output pressure from the regulator. Thats why I run mine at 1.5 bar, I would be very interested what others do though.


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