DubbieBoy

I am also using the Aqua-Medic CO2 gear and have been delighted with it. The kit includes an excellent reactor (requires pumped input) although the gas bottle is a little small (350g equates to about 500 ml I'd guess...). I use a solenoid to make the gas last (a lot longer). The equipment is well made, very unobtrusive, and I'd be happy to recommend it to anyone. But the proof of the pudding... The Aqua-Medic 350g bottle and regulator My 2ft (cube) planted tank This tank practically fizzes all evening!

Hi Ed, I have pm'ed you back but thought I'd post the gist of my reply to you to the list for the sake of discussion... Re: Aqua-Medic CO2 bottle... Of course CO2 is just the first step; as soon as you start to see the results you just get pulled in deeper and deeper (am now in the process of upgrading my lighting, sigh...). Anyway, in answer to your question about the gas bottle... Firstly, because its under 1kg, the bottle is not subject to the testing regulations which apply to larger bottles (its basically a soda-stream bottle). BOC won't touch it as they're pretty useless when it comes to dealing with anything other than their own stock, I've found them pretty unhelpful anyway.... I brought my bottle to the Cylinder Testing Station (in Dunedin); they're the sort of place that test LPG cylinders, SCUBA tanks and that sort of thing. They also supply CO2 for MIG welders and to the bar trade. Because they'd never handled a bottle that small before, they wanted to do a (once-off) volume test to confirm its capacity ($30), then they slapped a sticker on it, stamped the volume on the side and its been a $5 refill ever since. Initially a refill lasted me more or less exactly 6 weeks at a moderate flow of about 1 bubble/second. But because I wanted to get a bit longer out of the gas, I have since included a solenoid (again Aqua-Medic via Barry) so I now expect to get 2-3 months between fills. I'm comfortable with that. I don't know about Auckland but I'm sure there'll be a similar outfit (in the Dunedin Yellow Pages, the Cylinder Testing Station is listed under Gas-LPG Equipment). Its also possible that anywhere that refills soda-stream bottles may also be able to help (I noticed last week that Mitre 10 now offer this service...) but I've not tried this. What have I learned about the CO2 experience thus far... 1) Although its important to be aware of your water chemistry, don't get hung up on it. Unless you turn your tank into a jacuzzi of CO2 bubbles, I think you're unlikely to harm anything. 2) Fish don't really give a hoot about pH. Since installing the solenoid valve, the pH presumably bobs up and down a little bit between day and night. This morning I had two pairs of Angels both spawn on opposite corners of the tank; its World War III in there but I take it to be a pretty good sign that all's well. 3) Tighten that regulator on pretty tight with a spanner... You can test for leaks with soapy water. The regulator's rubber O-ring is pretty effective though. I've had no problems with leaks (yet...). 4) Be ready for the 'end of cylinder dump'. Keep an eye on the CO2 bottle pressure gauge (the right hand one) and as soon as you notice it start to drop you know that you've only got a couple of days of gas left. You can let it get quite low but if it drops below a certain threshold pressure, the regulator won't function and it will vent all of the remaining gas into the tank. Get a refill before this happens. 5) I put glycerol (available from a pharmacy or supermarket) in the bubble counter instead of water. Its slows down the bubbles, making them easier to count.

As it happens, I work in a lab but I'd prefer to get my own stocks rather than 'borrow' (and our stock of K2SO4 is a bit low at the moment anyway). Sigma chemical suppliers have K2SO4 (250g) for A$26 (or 1kg for A$70). MgSO4.7H20 (a.k.a. epsom salts) is A$40 for 500g. But these lab grade chemicals are likely far purer than we require for our plant fertilisation purposes - I'm guessing folks must have an alternative, and cheaper, source - perhaps from a garden centre? Warren - can you help?

Looking for a source of potassium sulfate and magnesium sulfate; where do folks obtain these from? Cheers and Happy Christmas to the list! In 2005 may your plants pearl, your fishes frolic and your tanks look terrific! Dubbie

Cracking setup Fay; can I ask where you ordered your plants from?

Hi Ballistic, I like my plants too; I think a heavily planted tank can be the most challenging, and the most rewarding, sort of setup. And they just look stunning! I posted up some pics of mine recently under a different topic, this link is... http://www.fnzas.org.nz/fishroom/viewtopic.php?t=3589 I think this 'Aquatic Plants' section is underused, there must be more planties out there...!

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

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 :-?

Chimera, The CO2 regulator is by Aqua-Medic (www.aqua-medic.de); details of the NZ distributor are further back up this thread, I got mine by contacting him directly. My regulator came as part of the set (bottle, regulator and reactor) but the regulator is available alone for NZ$169. - Rory

Thank you for that Bill; I guess I'm trying to summarise some of the information that I couldn't find anywhere when I was originally trying to put this together myself. I'm very pleased with the end result and always happy to share - Rory

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. 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... That's the bubble-counter stuck on the right hand side Front view The CO2 bottle and regulator in position - with a pottle of food for scale... The CO2 stuff hides away nicely at the back... The view from the other side.

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...

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... ), 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

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!

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. 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...

Just a point of information on this topic- If you go browsing the net for the bits and pieces to put a pressurised CO2 system together, you will quickly see that the American market has some wonderful, relatively inexpensive, specialist CO2 regulators and gas tanks which regularly come up on ebay and the like. Be warned though, these are not compatible with NZ fittings or BOC tanks (the Americans use a CGA 320 fitting whereas NZ uses the British/European equivalent - they're not interchangeable however...).

Since I started to include baking soda in the mix however, I have noticed that even a very small pinch of soda seems to completely prevent the sort of frothing that inspired my first post on this topic. Too much (by which I mean about a quarter of a teaspoon or so) seems to hold the brew back and it dies off prematurely but a very small pinch doesn't seem to harm the fermentation process and really does appear to prevent frothing, at least in my hands...

As far as I can see, Seachem themselves don't know how or why Excel has this effect on BBA although I think I remember reading somewhere that it somehow interferes with the wavelength at which BBA absorbs light (but this might have been somebody chancing their arm...). Certainly the BBA dramatically changes colour, turning a bright red just before it dies off, so the Excel is doing something to it. I bought it for its algicidal properties rather than as a plant fert (for which I'm using Flourish). Seachem have a very informative website...

If the outlet from a fermentation bottle were to be completely blocked somehow then I'd say any bottle is in serious danger of exploding as the pressure buildup would be enormous. I use a laboratory schott bottle which is very heavy pyrex glass (I used this as there was a suitable lid available for it with an already sealed outlet for a gas line). But there's nothing between the bottle and the tank to allow any significant buildup of gas pressure and, short of tightly knotting the tubing, I can't imagine how any bottle could build up enough pressure to explode but yes, you do hear the stories...! Do you think adding baking soda helps to prolong the culture any? Might try that...

Flourish Excel did the trick for me too. Black beard algae firstly turned red and then died away in about a week. Hasn't been back since. The odd thing is that this algicidal property is a just a side-effect, Excel is primarily a plant fert or, as Rob points out, a carbon supplement. Anyway, its great stuff. Good luck.

That's interesting; I usually just give it a thorough rinse out in hot water before starting a fresh brew. I've been using a 2 litre glass bottle as a fermentation vessel, I might try running it through the dishwasher next time to sterilise it and see if that makes any difference. At the moment, I use two cups of sugar, 1 level teaspoon of yeast and make it up to 1,800mls with warm water. It bubbles away steadily for about 10 days although it could probably go for longer if I let it. I had thought that the DIY CO2 route would be temporary until I got around to playing with a pressurised system but its really been working so well that I'm hard pushed to see the point of upgrading...

I got tired of small amounts of froth from yeast cultures bubbling up into the CO2 line and into the tank and making the water cloudy, sometimes a fresh brew bubbles up, sometimes it doesn't, who knows... The oft cited remedy to this problem is to attach a second bottle with a tube in and a tube out so that any froth gets trapped before it gets a chance to head tankwards. The only problem with this solution is that it requires two more seals to be made with the associated possibility of CO2 leakage. I recently tried putting a (new ) car petrol filter into the line just after the fermentation bottle; you know the ones with the paper element for filtering out crud from the fuel tank of older vehicles. They're completely sealed, seem to be made of polypropylene or something similar so should be CO2-proof and have appropriate attachments for hoses. My CO2 line fitted nice and snug. No more nasty goo entering the tank. Been running for two months now; works great.

That's interesting to note Warren; would you care to suggest an appropriate concentration of CaCl2?? Any other plants have high Ca requirements?

Riccia is pretty common; although I've never seen it for sale at a LFS. Its usually easier to get a starter piece from another hobbyist who might be prepared to mail some to you. I did get a bit through this list a little while ago from a very nice chap in Auckland but sadly, it didn't 'take' this time, I suspect there's a certain minimum amount needed for it to take off successfully and cover the water surface, it does like high light levels. Debbie from Redwood Aquatics suggested to me recently that they could get hold of some for me, as one of their customers apparently has some in a pond. You could perhaps contact them and see if they can obtain some extra... I suppose the best thing about Riccia is that your Oscars won't be able to touch it; it just floats back up

Try some Riccia fluitans - this small floater sucks out nutrients like nobody's business once it gets established. I had an Oscar tank some years ago with an inch thick covering of this plant on the surface; never saw any algae, fish seemed to find it calming too. Once established it grows exponentially and you'll end up scooping it out by the handful. And its a beautiful colour under good light.