from diy to pressurised in NZ

[ben]

I have been using diy co2 for a while and changing the bottles is getting old. I would like a pressurised setup but am not sure what to get here in NZ. I don't think I need one of those ph controller things at this stage. What is a good low-cost system for me?

Thanks for any help.

Ben

[Pegasus]

Hi Ben

Don't know if I said welcome, but it's nice to have you with us.

I was looking over some info on another board and came across this that might help you. I'm not into CO2 so I can't say if it will work, and the writer did say if anyone found any probs to let him know, so if you do have a prob I'll pass the address on if you contact me.

a way of injecting co2 into your tanks can be accomplished by mixing active yeast with water and bicarbonate of soda in an air tight bottle with a length of air hose leading from the top of the bottle into the tank via a power head as a diffuser, i personally have tried this and is an affordable way of injecting co2 when on a tight budget.like me.

Hope this helps

Pegasus.

[Rob]

Hopefully Warren will chance across this thread and reply as he is familiar with what you're getting at - tired of having to keep yeast bottles going etc and want a less labour intensive/more stable way of getting CO2 into the tank.

From discussions with the 'Plant' people in our local club (there's 2 of them that I consider plant people) - the way to go is to hire one of those industrial CO2 cylinders (not necessarily one of those huge mommas that you'd have to use as a coat rack - there are more appropriate sizes), fit it with an appropiate regulator and fit it to some sort of bubble device in the tank. I don't use CO2 myself but I understand that there is a relationship between hardness of water, CO2 content and pH (you're probably more familiar with this than I as you've already been CO2'ing) that you need to be aware of to avoid the pH bottoming out.

The local plant people don't like the high price of the 'professional' aquarium CO2 systems that you can buy and make the comment that you end up having to get the tiny cylinder filled up more oftne than they would like.

From my standpoint (based on shaky knowledge of CO2 systems) important considerations (other than cylinder size) would be a suitable regulator so you can get the fine control required and what grade of CO2 (I assume they have different grades) - I'd tend to steer away from industrial grade and opt for food grade.

If Warren for some strange reason doesn't come across your post and you're wanting more specifics give him an email - he's usually happy to discuss the requirements for growing aquatic plants.

[Warren]

Yip, Rob was right, it was only a matter of time...

Well, here goes. I did a lot of research into CO2 and what was cheapest both short and long-term.

At the risk of blowing off my own foot, here goes:

The best solution I found (while still not all that cheap) is;

Rent a 6.8kg Food Grade CO2 cylinder from BOC gasses - approx $108/year.

Buy a gas regulator for CO2 (stainless steel guts) - $140.00.

Get a gas solenoid (230VAC) from a pneumatic supply shop - $60.00

Connect the gas solenoid to the output of the gas regulator and wire it to your lighting timer.

You are ready. You'll need to make up a needle valve and bubble counter.

You can feed the gas into your canister filter return - what no canister or trickle filter !!!!!!!!!!!! and !!!!!!!!?

Its still not cheap, but is a lot cheaper than alternatives. You can muck around with soda stream, but the fittings are dodgy and unreliable. Using proper industrial gear means no hastles. Also soda stream and other alternative cylinders need to be checked regularly and cost extra to have filled. The BOC cylinder while it costs a little to rent each year never needs to be tested (as they do it within the rental cost) and there is no premium on refills ($22.00 per refill for 6.8kg bottle).

My 6.8kg bottle lasts about 2 years on a heavily planted 1200L tank. It costs 10x more to rent the cylinder than it does for gas!

I hope this helps.

[ben]

That's exactly what I wanted to know, Warren

But tell me, why do I need to wire it to my lighting timer? I'm from the school of thought that says leave the co2 on all the time, and if you run into problems, aerate at night. Which is what I do at the moment. I take it that wiring it to the lighting timer would mean co2 injection during the photoperiod and not at night?

My other question refers to the needle valve. Are these things easily made? It sounds a wee bit daunting. Can I buy one instead? Of course, if they're not hard to make I'll save my money...

And finally, do I buy the regulator from BOC or somewhere else? And where would I find a pneumatic supply shop in the greater Wellington area? Or at least, whereabouts would I find such a shop in the yellow pages?

Thanks very much for the info. I'm 100 times closer to pressurised co2 than I was this time yesterday!

Ben

[cees]

my 2 cents.

If you're on a budget you can leave out the solenoid and spent the $ on a good quality needle valve, sometimes called 'metering valve'.

You can get away with a plastic petshop valve but it works much better with a good quality valve.

A starting point for a supplier could be 'Alltech New Zealand' in Auckland

[email protected] (at least according to my latest catalog).

Not sure wich one you would need but a Nupro B-4MG2 has been mentioned on other sites.

http://aquaticconcepts.thekrib.com/Articles/book.htm

[Pegasus]

Just a suggestion, but the Warehouse and other places carry perfectly good "Needle Valve" type fittings made of brass and s/s on their cast iron gas rings, single or double. If you catch them at sale time you'll get a set for under twenty bucks. Both valves are mounted on approx 10-12mm brass or copper tube and could be easily converted as they are detachable with a couple of screws.

[Warren]

BOC sells the regulators at the price I mentioned.

I make my needle valve. First go to a car wreckers and get the threaded needle part off an old carburetor. Next get a brass rod 40mm long and 10mm diameter and drill a 1.0mm diameter hole right down its middle. Next, drill a 3mm diameter hole in about 5mm at one end. Next, drill a hole about half way through from the other end the correct size to tap a thread for the needle. Tap this section to fit the needle. You will now have a rod with a diameter 3mm hole reducing to 1mm diameter then increasing to a threaded section for the needle. Next, drill a 3mm hole from the side of the rod into the threaded section almost where the thread meetes the 1mm section. Get some 3mm diameter copper of brass hollow rod and cut 2 pieces 20mm long. Fit 1 into each of the 3mm holes and solder in place. Get an O-ring from somewhere like SKF bearings that fits tightly over the needle and inside the threaded hole. This seals the thread so gas does not leak out. Put a little bit of vaseline in the threads to further help the seal. Fit the needle to the finished housing and you have a completed needle valve, - total cost about 5 bucks and 30 minutes work.

If you are going to buy a needle valve, make sure the needle is very small in diameter and quite long (Dia 1.5mm, 15mm long is good).

This gives you maximum adjustment for minimum gas flow change.

Don't skimp on anything when it comes to CO2. If you make a mistake, or the needle valve has a mind of its own (watch out for temperature changes - they can change the gas flow), it could wipe out all your fish!

I wire to the lighting timer to turn the gas off at night. I do not aerate at all. I could probably still leave the CO2 going, but its just a precationary measure that I turn it off.

[Pegasus]

Just a laugh. Perhaps we should change to the DIY section.

Well, up to now this valve thing was all making sense, but I just spent an hour or so down at the wreckers yard scrounging about for a threaded carby needle, then with grease up to my armpits another trip to the engineers for some 10mm brass rod. Got home.... BLAST... forgot to pick up the 1mm drill and the special tap that probably will be a bastard size that the local hardware won't have, but I can risk another trip. Then I'm gonna need a 3mm drill as well, and I have to drill along the length of the 40mm brass rod with the 1mm drill. Geez... This is gonna be fun getting it acurate, even in the lathe. Then I have to drill in the sides of the brass rod, so I'll need my vice.

My soldering iron ain't big enough for this job... (electronics job) Oh.. and I'll need some copper pipe. Well... There's ten bucks worth of gas gone not counting all the bits and pieces, plus the expensive gun tap that I finished up going back to the engineers for.

All I can say is you must have a bloody good workshop Warren, with either a very accurate lathe or a perfect pedestal drill stand, not counting all the other bits like number drills, taps, possibly up to 30/40tpi, tap wrenches, thread guages, drill vice, vernier or micrometer, blowtorch, Duzall, solder, lapping in compound for the taper needle because no drill will match a taper needle.

This is precision engineering. My last 15 years were spent designing and building industrial robots and work aids for the sewing industry using electropneumatics, hydralics and such, but when it came to valves, precision was the word, and although the Warehouse valves I mentioned are not 'precision' as such, I know where I would spend my 20 bucks for a simple regulator, and you'll get two for that price.

Like you say, it is almost impossible to get constant acurate flows from a needle valve due to temperature fluctuations, so something like an RO6 from Norgren would be the answer, this being a spring diaphram type regulator which will control flow under all conditions, but damned expensive.

A simple NE555 timer circuit, that even a first timer to electronics could build is available in kit form from DSE and could control a simple solenoid to shut the CO2 flow off and would run for possibly years from a 9v battery and be independent of power failure. Set to turn on and off every hour or so would reduce costs. (See data section DSE catalog)

This is all in good fun Warren, and I hope you take it as such, and I have no doubts whatsoever that you could make your own valves, but it really is just beyond the 'average' kiwi bloke I would think.

Pegasus.

[Warren]

You are possibly right. I do have a fairly good workshop available to me. Most of the bits are off the shelf. There is however a possibilty you may not have considered, - why do it yourself if someone you know can do it for you. Most of us know someone with enough skills to do the job.

The tools I used to make my last needle valve were: Drill Press, Soldering Iron, Solder, 1mm Drill Bit, 3mm Drill Bit, 11/32 UNF Tap and a Machine Vice.

Next issue... The 555 Timer. As some of you may know, I am an electronics engineer. I thought I should point out an issue or two regarding this item. While the DSE timer kit is a great product it will not work for long off a 9V Battery. The current draw from a 555 chip is mA. It will only last 1-2 days on a 9V battery. Even if you change the chip to a low-power cmos 7555 version it still will not last long. If you add the coil current from a relay or solenoid the battery will go flat even quicker. 9V batteries do not have a large amount of energy stored in them.

If you want to use this kit (as it is a good idea) you will need to power it from a 9V plugpack. A battery may be diode fed into the circuit to supply power during mains failure, but its state of charge will need to be checked regularly.

[Pegasus]

Touch'e... 555 point taken.

The 555 or similar could run a micro relay of low drain and switch an independent relay for the solenoid, which of course would not run from the battery circuit. The thought was there and you would still have a high drain.

Just trying to get away from relying on the mains.

Must get a new catalog... Mines pretty old,... Errr.. 19....

Good info Warren as always.

Regards

Pegasus.

[Lenbok]

I make my needle valve. First go to a car wreckers and get the threaded needle part off an old carburetor.

Don't skimp on anything when it comes to CO2. If you make a mistake, or the needle valve has a mind of its own (watch out for temperature changes - they can change the gas flow), it could wipe out all your fish!

Gads you're hard case, Warren -- making needle valves sounds like a ball!

Another data point (I had this info kicking around on my computer...)

My CO2 bottle hire is $9 per month

My regulator is a "mini reg" oxyturbo made in italy ($70)

My needle valve is a Pneumax 6.01.18/5 ($50)

They all work fine. The CO2 bottle (6kg or so) lasts at least a couple of years on my 200l tank.

I don't bother having the co2 on a timer and the only fish-killing experience I've had was when my (then) 2.5 year old daughter cranked the needle valve right open while I was at work. (from 1 bubble per sec to about 20 per sec). Goodbye everything except a few killie fry.

Cheers,

Len.

[Warren]

Hmmm... Even more reason to DIY. You could make small cap over the adjuster to make it kid-proof. Why pay for it if you can make it.

[Lenbok]

Hmmm... Even more reason to DIY. You could make small cap over the adjuster to make it kid-proof. Why pay for it if you can make it.

When you get kids, you'll understand that the most significant factor against DIY is the time factor :-) (unless you can get the kids into helping, like when I made a new whiteworm culture today).

The amount of time I've got available to spend on my fish and carnivorous plants has taken a massive dive since they arrived on the scene...