Paintball CO2 setups

[LuminousAphid]

Hey guys, I was just at Aquarium Co-Op the other day for the first time in a while, and saw that they have a nice little regulator and solenoid setup for paintball-sized CO2 tanks with the smaller, nonstandard fitting, and was really thinking about getting one. I already have a 16oz tank from a friend, and can possibly get more for very cheap.

My main concern is how long the small tanks will last. I have a 20 gallon tank that I would plan on using it for, so nothing huge. I don't really want to be running out and getting refills every few days, but if it lasted maybe 2 weeks or more I could be OK with that. I suppose it depends on how much I want dissolved; I would go for the lower end of the scale since boosting it up higher just means more trimming and more refills.

Anyone have experience with these and can give me an idea of how long a 16 or 20 oz tank might last me? Any other feedback or help would also be appreciated
(sorry if this has been posted, I didn't really do a search for it)

 

[dleblanc]

I don't have fine-grained data on this, but a 10# tank has lasted close to a year in my 55 gallon tank, and hasn't run out yet. The small tanks are a lot more convenient - a full size 5 or 10# tank with regulator will take up some space, but in long term price, it was only $15 for 10#. Though if I'm only running through 10#/year, it will take forever for me to get ahead.

Something to very much look into is a pH controller. I had problems trying to run CO2 without one. The Milwaukee controller will do, and is about $100.

 

[Anonymous]

On the low end you'll get a couple months usage out of a 1 pound tank with moderate use in a 20 gallon tank. This is assuming you'll use a timer at 8-12 hours a day on at about 1-2 bubbles per second.

 

[dleblanc]

Two things here - first is to always use a CO2 reactor. This can range from this at $45:
http://www.aquariumplants.com/Aqua_Medic_CO2_Reactor_500_p/71111.htm

To this:
http://www.aquariumplants.com/CarbonDoser_EXT5000_External_Reactor_50000_p/ext5000.htm

Which is $110, and works well for anywhere from about 50 to 200 gallons. I have the little one on my 20 gallon, big ones on the 55 and 180. This makes it so that the CO2 won't escape the reactor until it is dissolved in the water. This saves you a _lot_.

If you have a pH controller, then you don't have to worry about the timer, or wide fluctuations in pH. I tried to cheap out with the pH controller on the 20, had the bubble count set really low, and found that all sorts of things made it fluctuate over time. After coming down to find my pH at around 6.3, and the CO2 concentration up around 40 ppm (which gets into the toxic range for fish), I got a controller, haven't had to dink with it since.

I also would strongly urge anyone using pressurized CO2 to get a handheld pH meter - they're only about $25 on Amazon.

 

[tazeat]

There are several schools of thought on this...

1) diffuser options, you don't "need" a reactor, the gla atomic ones work fine too. The filter return diffusers are highly rated too, but I've never used one. There are options.

2) regulators. I wouldn't spend under 100 but you can do GLAs atomic regulator for 135 which I'll vouch for being good and reliable or go with like UP or one of the Asian ones for around that price and hope it works out, build your own out of used parts for a nice dual stage, or spend up to 300 for a good one. All options, I'm not familiar with the paintball models. The Asian ones I'd watch out for crappy needle valves and the solenoid, replace just those parts if needed... I usually try and configure it so that if the solenoid goes out there's enough aeration at night I wouldn't kill the fish, even a Ph controller wont save you here. Or really any single part failure for that matter, scares me to be honest, read too many stories of people killing their fish. Keep a drop checker and watch it religiously especially if you've been changing anything until you're familiar with your setup. Oh and a quality needle valve is worth its weight in gold. The piece of crap on my Asian regulator wandered and was almost impossible to get it set right, the fabco I put on the regulator I built I set and haven't touched for months, it's still dead on, I only use a timer. I'm curious which paintball regulator aquarium coop has, they usually seem pretty careful not to sell crap, so that's a good thing at least.

3) tanks... The smaller the tank the more you'll spend per ounce on the co2 period. 20 lb tanks are found on craigslist for 60ish quite often since they're used for beer and soda all the time, that's my recommendation, cheap to fill and last forever. A 5 lb might be easier to fit and hide behind your tank however.

The cheap <$30 ph meters I've also found quite useless unless you calibrate them every time you use them. The liquid tests seem to be much more repeatable YMMV, a better ph meter I'd say is a nice to have. On eBay I've seen some all the time ph meters coming from the Asian markets that looked like they may make nice monitoring equipment, they stay on the side of your tank, I think the big thing that screws up the calibration IMHO for the ph meters is drying them out and rewetting them repeatedly.

Remember a drop checker is just Ph fluid that stays on your tank all the time... and lags the co2 in the tank by about an hour.

 

[dleblanc]

These are expensive, but work really well - http://www.aquariumplants.com/CarbonDoser_Electronic_Co2_Regulator_p/co2.htm. Basically, when I considered the consequences of a failure, I felt like this was reasonable insurance. They also have an adapter to hook these to a paintball cartridge. I'm in complete agreement with not cheaping out on the regulator or the solenoid.

Aeration is not going to save you. It is very possible for water to be high in CO2 and oxygen at the same time. It is a law of physics that the concentration of a gas in a liquid is independent of the concentration of another gas. What might save you from disaster is something like a sump, where you have a lot of surface area for gas transfer, and the CO2 can get back out again.

The 20# tanks are available, but they are taller. Unless you have a really tall stand, or will put the tank outside the stand, then a 10# is what will fit. A 10# tank is just under 21", a 20# tank is just over 27". She's only going to use it on a 20 gallon tank, and at the rate I've been going, 20 gallons would last about 3 years on a 10# tank.

I've had good luck with the Milwaukee handheld for $25, and I don't calibrate it every time. Only downside I see is that it is slow to read. I take some water, put it in a cup, put the probe in, and check it 3-4 minutes later. Other than that, it reads as well as my Pinpoint that cost $100 (though that one is a lot more precise). I think if you know your pH within +/- 0.1, that's good enough, at least for starters.

I would start with a $45 reactor, a $25 pH meter, plan on not being aggressive. Also, get a chart of the relationship between KH, pH and CO2 ppm, test a lot when you start out. I have this in an Excel spreadsheet with the danger zone color coded if anyone wants it. If you find that your pH is all over the place, or goes dangerously low, then the next thing to get is the pH controller. If you're really happy with how your plants do, then save up and get the good stuff. I started with the cheap reactor and pop bottles full of sugar and yeast.

 

[tazeat]

Well to be fair aeration brings the co2 closer to equilibrium with the contact with the air reducing the higher than air co2 concentrations... The difference with a drop checker is substantial after adding additional aeration for reducing co2.

My experience with the cheap handhelds is +/-.3 at best every time I calibrated... Mine was generic Chinese crap though.

 

[dleblanc]

The Milwaukee 600AQ has been very close to my Pinpoint every time I've checked. It is _much_ slower to respond, and it is only rated at +/- 0.1, but it has been within that range when compared with the Pinpoint. It is worth getting a couple of bottles of calibration fluid - the packets are a pain.

 

[LuminousAphid]

Ok, all of this has at least made me decide, once again, that I am not going to run CO2 at this stage. I would have to be way more into plants to make all the money, time and effort worthwhile. I was just thinking about a simple set-up that wouldn't cost me much, but that doesn't seem to be a thing.

Thanks for all the info anyway, I will save this thread for the future in case I change my mind.

 

[Anonymous]

Ok, all of this has at least made me decide, once again, that I am not going to run CO2 at this stage. I would have to be way more into plants to make all the money, time and effort worthwhile. I was just thinking about a simple set-up that wouldn't cost me much, but that doesn't seem to be a thing.

Thanks for all the info anyway, I will save this thread for the future in case I change my mind.

WHAT?!?! With a bit of time shopping around I am sure you could find something for around $100. Perhaps cheaper. I think AquariumCoop has complete systems brand new for a decent price. I have lines and defusers collecting dust waiting to be used. Come get them, or pay shipping and Merry Christmas!


Everyone is tripping with the hard core expencive equipment. IT'S NOT necessary! All you need is a tank, regulator with silnoid, and a defuser! I would recommend a drop checker but again, not necessarily.

 

[Anonymous]

I think I even have an extra drop checker...

 

[Chiisai]

Well to be fair aeration brings the co2 closer to equilibrium with the contact with the air reducing the higher than air co2 concentrations... The difference with a drop checker is substantial after adding additional aeration for reducing co2.

My experience with the cheap handhelds is +/-.3 at best every time I calibrated... Mine was generic Chinese crap though.

Why would you aerate to reduce co2 when the goal is to add co2? Additionally (im trying to remember chemistry) co2 would add aeration into the tank as the plants remove the carbon the oxygen is released.

 

[tazeat]

Like I said, I like to have enough night time aeration so that if the solenoid sticks open (which happens, see plantedtank or any of the forums where this has happened to people) that there would be enough aeration that the fish would be ok. Photosynthesis does not occur without light.

 

[dleblanc]

As to cheap, you can easily do this for well under $100. I started with the little reactor and pop bottles with yeast and sugar. Unless you get hot rod yeast from the home brew store, you're really unlikely to OD the tank with one. I'd go two bottles, stagger them.

The chemistry is this - the concentration of two gasses in a liquid are completely unrelated. But when we run CO2 injected, we tend to get a higher CO2 ppm than you would get in equilibrium with air. So anything that disturbs the water - going through a sump, a HOB filter, etc. will tend to pull CO2 out of the water. When you inject air bubbles, it disturbs the water, and as oxygen dissolves into the water (since the aquarium is normally below equilibrium), the CO2 is going the other direction.

I'm quite skeptical that any amount of aeration, short of a wet-dry sump is going to overcome a pressurized CO2 canister just dumping all the CO2 into the water. I could be wrong - we could experiment if we wanted.

The next bit of chemistry - plants produce oxygen, and consume CO2 when the lights are on, the reverse happens at night. This is why many people turn on extra bubblers at night. The only way to know for sure if you need this is to test the dissolved oxygen, but DO meters are not cheap. If you have a pH controller, then it will compensate for overloading CO2 - the CO2 will just go off for most of the night. It won't help with the plants consuming oxygen. However, from my testing with a DO meter on my tanks, and a friend's tank as well, there isn't a huge difference morning to evening.

 

[LuminousAphid]

That's very interesting, I didn't know until this thread that gas concentration is independent between gasses. I always assumed, wrongly I guess, that as the CO2 concentration went up, oxygen concentration went down, but you're saying this is not the case? So when people on forums talk about suffocating their fish with too much C02, they are making the same assumptions and are incorrect... It's actually the CO2 over-concentration that's poisoning the fish then, not a lack of oxygen?

If I do want to try out the yeast and sugar method, can I still use a solenoid to time the setup to stop at night? Also has anyone been able to pull off a multi-day supply with this method? Those are the main reasons I have never tried yeast; I don't want to (and often can't) be home to turn on/off the system at the proper times, and also don't want to mess with making the mixture fresh every day. I know, I am lazy, but I have come to terms with that.

Thanks so much everyone for all of your help on the topic, I'm glad it has sparked some discussion and glad I learned some things from the responses.

 

[dleblanc]

Correct - the concentration of CO2 is too high. The other thing that happens is that KH, pH and CO2 concentration are all linked. So let's say we were running really conservative CO2, KH is 5, and pH of 7.0. That yields a CO2 concentration of 15 ppm. Now if the CO2 tank just dumps into the tank, say it drives the CO2 to 60 ppm. The pH is going to drop very quickly to 6.4! So between the CO2 going way too high, and the water turning very acid very quickly, that's a huge problem.

My sugar and yeast bottles usually lasted about 2 weeks. One thing to look out for - they bubble right along, and then completely quit. So I'd change one out every week, then change the other. I never had any sort of controller on it with the yeast, didn't want the pop bottles to explode. They usually don't make enough CO2 to be a problem. The pop bottles do like to be warm, though - if they get chilly, they won't do anything.

 

[jrygel]

That's very interesting, I didn't know until this thread that gas concentration is independent between gasses. I always assumed, wrongly I guess, that as the CO2 concentration went up, oxygen concentration went down, but you're saying this is not the case? So when people on forums talk about suffocating their fish with too much C02, they are making the same assumptions and are incorrect... It's actually the CO2 over-concentration that's poisoning the fish then, not a lack of oxygen?

That being said (and I believe it is correct). The discussion of adding aeration at night to negate excess CO2 is still somewhat valid: the increase in O2 in the water may not help you, but the increased agitation will help more of the CO2 to dissipate out of the water.

 

[dleblanc]

The additional oxygen does help - after playing with a dissolved oxygen meter, I think many tanks are low on oxygen and don't know it. We have one that is heavily planted and seemingly lightly stocked that was really low.

What I don't think it will help much with is if something goes wrong and the regulator just dumps a bunch of CO2 into the water. I think the resulting pH swing and high CO2 concentration is going be a major problem. Only thing that might stave off disaster is a sump that allows a lot of gas transfer.

It would be an interesting thing to experiment with, Mythbusters style - get some CO2, maybe a 55 gallon tank, and see just what happens. Obviously without fish.

 

[Anonymous]

In the last 5+ years I've experianced a lot of things dealing with CO2 injection. Too much CO2 the fish will die. The combination of PH swing, water paramiter swing to acidity is too much for fish to bear. The opposite can happen too. If you have a consistent CO2 supply all inhabitants become accustomed to the water paramiters. If the gas is cut off the swing of water paramiters can be deadly.

The key is to have a nice soft transition . Recommendations of having the CO2 come on an hour before the lights, then switch off and hour before the lights turn off is all about introducing a gentle adjustment of concentration of CO2 in the water.

It is possible to keep CO2 running 24/7. Using the DYI method a lot of times this is unavoidable. Normally the DYI method can only produce little amounts of CO2 with very little pressure. The only defuser I was successful with using DYI CO2 is the ladder and the upside down cup diffuser. Ultimately it was tough to put enough CO2 Into the tank using DYI. But it's a good introduction to this part of the hobby. Unfortunately the method of running the system 24/7 is trial by error. If fish die, then it's too much... doh.

I've never had a silnoid fail (yet). However if it does I am pretty confident my systems will maintain okay without crashing too much. It may still stress the fish a bit. Both system are aerated pretty darn well though. Sump on the 140 and a big airpump running 24/7 on my 29 gallon.

 

[dleblanc]

I am going through CO2 a LOT faster with my 180 with the sump. The high side has dropped to about 700 psi, so it has used more in 2 months than my 55 has used in almost a year. There's 4 times the water volume, so that's somewhat to be expected. But I also think the sump is causing it to lose CO2, which is mostly OK - CO2 isn't _that_ expensive.

How low do you let your CO2 tank go before you swap out a fresh one?

Here's what you do with DIY in terms of not making errors - get the chart that shows CO2 ppm as a function of KH and pH. Test for both, see what the ppm is during the day, check it again first thing in the morning before the lights come on - this will be a peak. I was never able to get the DIY unit to make enough CO2 to remotely come close to overdosing. Obviously, you can also regulate this by using different size pop bottles with more or less sugar and yeast.

What I ran into is that the DIY just stops. As you pointed out, then the pH swings up. This didn't seem to annoy the tetras very much - they're mostly pretty tolerant fish. But I thought the discus that I wanted to put in there would Not Be Amused. So I decided that a pH controller was the way to go - keeps things nice and steady, and even compensates for pH fluctuations due to water changes.