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complete pressurized CO2 system


edmondsng

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Hi

What is the cheapest way to put together a complete pressurized co2 system? I tried BOC gas last week and they don't seem to have what I am looking for. The cylinder is 6.5kg which is way too big.

I am aware that a eheim or JBL system would cost somewhere between $1500 to $2000.

I will be very grateful if someone could give me some pointers as to where I can get all the neccesary parts at a reasonable price.

Many thanks

Ed

:D

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Hi Ed,

I guess it depends on what you're after, how much you can spend and whether you want to cobble something together yourself or get a 'system'. There's lots of tips and pointers out there for home-made setups and how to use welding regulators and convert old carburettors into needle valves etc...

I'm in the process of establishing a pressurised system myself and I'm under no illusions as to my own handiness so I'm opting for the 'comes in a box' approach. :wink:

You can certainly do a lot better than $1,500 - 2,000 tho'... (where did you get THOSE numbers from??) I'm going for the Aqua-Medic set which goes for $360 and includes the appropriate regulator (with integral needle valve), reactor and a neat little 350g CO2 bottle.

Alternatively, you can get the regulator (the most important component) on its own for $169. After looking around town (Dunedin) for a suitable bottle though, the best I could find was $200 for a ratty, reconditioned fire-extinguisher which had been re-valved but was still far bigger (and way uglier) than I wanted sitting in my living room... I'm not sure how long I'll get out of a 350g bottle but its refillable by BOC and, apparently, as its under 1kg, its not subject to the same inspection regimen as standard gas cylinders. I may opt for a second bottle at a later date as backup.

Details of the Aqua-Medic products are at www.aqua-medic.de , follow the links... The NZ distributor is Barry Torkington

Do not try and purchase pressurised CO2 products from the US however as, although they may be a bit cheaper, the fittings are not compatible with NZ ones and you won't be able to get refills...

The set should be here soon, I'll let you know how I get on with it...

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  • 2 weeks later...

The Aqua-Medic CO2 set arrived and has been installed; I'm really pleased with it, very neat and unobtrusive. It cost $5 to fill the bottle (same cost as a soda-stream refill apparently), it remains to be seen how long that goes for. It took a bit of fiddling to get the gas flow right but once set its seems stable.

One thing I had to watch out for was I had to raise my KH slowly over a few days to stop the pH dipping too low (got down to 6.2 initially) as the water in Dunedin seems to be really soft but it seems steady now at pH 6.8 with a KH of about 2. I will work towards getting the KH up a bit higher to provide a little more buffering capacity.

I might take some pics tonight and post them up; tank's looking great! :P

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Hi Dubbieboy,

Nice to hear from you again. I have sent a few e-mails to Barry but he hasn't reply yet. I am itching to get the system as well. Might be thinking of getting a PH meter as well. But before I can do that he has to reply to my e-mail first. :D

Look forward to seeing your tank.

Regards

Ed

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Hi Ed,

If you keep your carbonate hardness value up at around 4dKH, the system is better able to buffer against minor pH swings; here in Dunedin the water is very soft, maybe KH of 1-2 and a GH of 1 out of the tap. I raised the KH with sodium bicarbonate (NaHCO3 - a.k.a. baking soda (not baking powder... :wink:), there's a rule of thumb that 1 tspn, or about 6g, should raise the KH of 50 litres by 4dKH. I did this slowly over a couple of days and it worked just fine. I now have a KH of 4 and a steady pH of 6.8. The water chemistry may be totally different in your area though so I'd recommend you get a test-kit for KH. Don't get too hung up on it though, I think we worry about these parameters far more than the fish ever do! As long as any changes are made gradually the fish will be happy.

I do use a digital pH meter to monitor things, its a useful if not essential accessory for a pressurised CO2 setup I think (and I found the regular colour-change pH test kits far too vague). I picked one up from Dick Smith electronics for $129 but keep an eye on TradeMe as they come up surprisingly often (a brand new pH meter exactly the same as mine sold last week for $65 :( ).

The Aqua-medic set doesn't come with a solenoid valve although they are available. I'm not convinced that they're really necessary unless you really want to save on gas. My feeling is that I'm better off keeping these parameters as steady and constant as possible and I honestly don't believe the fish give a hoot one way or another if the CO2 stays on at night or not. The pH reads the same first thing in the morning and last thing at night.

I'm sure Barry will get back to you soon although if you look up his contact details on the aqua-medic website I'm pretty sure there was a phone no. listed if you want to speak to him directly. I shall endeavor to take some pics tonight and post them up here, really.

DubbieBoy

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Ed,

One thing I would mention to you as you are considering this system is that the Aqua-Medic reactor unit requires a source of water current to operate properly and this isn't really obvious from their blurb. Basically, it means that the outlet from any small water pump (such as an internal filter) is directed in through the top of the reactor body so that the CO2 is quickly dissolved in the counter-current. I found that my (Fluval 404) filter was too powerful and that having the reactor attached to the filter greatly impeded its performance so I have detached the filter from the reactor and will now try and source a small, cheap powerhead just the run the CO2 reactor alone.

In the meantime I am using a passive reactor ('bubbles run up the spiral tube and dissolve' affair) that I had been using for DIY CO2 injection, which is working just fine for now.

In short, the supplied reactor with the Aqua-Medic set requires a (probably additional) pump.

Just so's you know... :wink:

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Ed,

Some pics of the tank with the CO2 system in place... The tank is cube-shaped, 2ft to a side. I liked the non-standard dimensions and the extra depth makes the plants look more in proportion than the usual rectangular box shape, although some are now growing out the top. This tank has had DIY CO2 going for some time so the plants were already going strong before the pressurised system went on. The lamp is an Osram Floraset 80W HQl which seems to be doing a decent job. No algae to speak of although there was some BBA in the early days which thankfully has since died off. Fish include 4 angels, 3 blue rams, 4 bristlenose cats, 5 bronze corys, 8(ish?) glowlight tetras, 4 platys (all girls), a mob of cardinals (long given up trying to count them), 6 tiger barbs and 3 siamese flying foxes. Other than CO2, the plants get Seachem Flourish weekly.

P1010026.jpg

The tank is in the corner of the room; that's Phoebe in her usual spot sat on top - she spends hours totally transfixed by the bristlenose cats - its cat TV! Sorry the pics came out a little dark...

P1010018.jpg

That's the bubble-counter stuck on the right hand side

P1010021.jpg

Front view

P1010032.jpg

The CO2 bottle and regulator in position - with a pottle of food for scale...

P1010033.jpg

The CO2 stuff hides away nicely at the back...

P1010035.jpg

The view from the other side.

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Luke* - the line coming off the regulator is standard size (1/8 inch?) tubing but is not regular LFS air-line which is too CO2-permeable. Its a specifically CO2-proof tubing but, from what I understand from reading around, as long as you're using good quality silicone tubing (rather than el-cheapo PVC) then CO2 loss through the gasline is minimal. There's also a Dennerle CO2 check-valve on there just before the regulator to guard against the possibility of a back-siphon into the regulator. There's a second check-valve incorporated into the bubble-counter (paranoia). Its worth noting that regular air-pump non-return valves, the ones with the internal rubber nipple thingy, are not suitable as CO2 will attack and degrade them, quickly making them useless.

As regards the reactor, at the moment I'm using a passive reactor until I get a small pump organised to power the Aqua-Medic one. The passive reactor is a 'JBL CO2 Vario' unit, essentially just a hollow tube with a spiral winding up the middle. The gas enters at the bottom and spirals up, dissolving as it goes. Gas bubbles are large as they enter the reactor and quite tiny by the time they reach the top so yes, I think its pretty effective. Placing it in the outflow from the filter and creating some water movement around it helped a lot. A certain amount of gas does collect in a reservoir at the top and gets burped off occasionally but I don't think its undissolved CO2. Every gas bubble that enters the water will, while dissolving CO2 into the water, also absorb some other gases from the water, and its these gases which accumulate and have to be vented. I did notice a big difference between the rate of absorbtion of DIY CO2 vs Bottled CO2 though, which was interesting. The DIY, yeast-generated, CO2 bubbles didn't dissolve nearly as quickly as the bottled stuff and accumulated at the top much faster whereas the bottled gas bubbles are almost completely gone by the time they reach the top. I don't know why this should be.

The reactor is (just) visible in one of the pics, in the last shot the black CO2 line is visible entering the top of the reactor. More details of the JBL reactor, and pictures, are available on their website. I can't comment yet on the effectiveness of the Aqua-Medic reactor as I haven't hooked it up yet but my guess is it will be hugely more effective as it pushes CO2 bubbles against a water current. I'm hoping it will be more than adequate.

Ed - In answer to your question, in the foreground I've got dwarf sag (Sagittaria microfolia, which does really well, LOVES the CO2 - never really grew well without it), and hair grass (Eleocharis acicularis). There's a couple of other smaller plants which quite frankly I haven't got a clue what they are, some sort of cryptocoryne species I think. You know yourself, you see it in the shop, staff haven't a clue either, you stick it in anyway (for the record, this is not my attitude with fish...). My approach has been to give it a try - you see quickly enough whether a certain plant will flourish under your conditions or not. I would love to be able to just decide which particular plant species to put in and tailor them to the aquascape, just like fish really, and be able to get them but sadly, with plants in NZ you just have to take what you can get :-?

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hi, I've been reading all the comments so far about CO2 systems. I'm really keen, i've been wanting to convert my 70gallon tank to planted for ages now. done lots of research, and i'm interested that you guys say you can't use american CO2 equipment due to incompatibilty. Is it american CO2 bottles that are incompatible with NZ CO2 suppliers, or american C02 systems incompatible with NZ bottles? it's just that i've found some cheap CO2 systems that are ph controlled, and i'd really like one of these. can you get a ph controlled system in NZ? i've looked into the eheim system, and this will be at least $1300 from the pet shop.

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Both American and Eurpoean gagues will work just fine (I have both). Its the thread used to connect to the bottle thats the issues, and this can be solved with a feat of engeneering if needed.

Good luck. Lots of cheap gagues on EBAY.

Pies

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Yes, its the thread between the regulator and the bottle that would cause issues - American regulators use a CGA320 fitting whereas in NZ we use the British/European equivalent and these don't connect to each other. There's a comparison of the two fittings here -

http://www.teamonslaught.fsnet.co.uk/co2_info.htm

My guess is that your local CO2 supplier won't want to have anything to do with a non-standard bottle so you'd probably be looking at trying to get some sort of adaptor to allow a US regulator to fit an NZ bottle. Pies - have you found something like this?

Bear in mind also that if you buy a CO2 Controller from the US you'll also require a stepdown transformer to bring down the NZ 240V to an American 110V. Ditto any regulator which has a solenoid valve attached. Keep in mind as well the availablility of replacement pH probes.

If you can safely connect bottle and regulator as Pies says, there shouldn't be any major problem, the rest is just water chemistry and that at least is standard worldwide :wink:

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