Should i run co2 24/7 or not?

[Kristian Tombs]

I have a spray bar on my filter so there is plenty. It is gonna be my first pressurised co2 so I want it to be cheap. So I was wondering whether to get a regulator with or without a regulator?

 

[sodbuster95]

I assume you mean a regulator with or without a solenoid so that you can connect the CO2 to a timer.

This setup is not strictly necessary. However, many people note that injecting CO2 during night hours may cause your levels to rise above a level your fish are comfortable with. This is a result of the fact that plants only use CO2 during photosynthesis. At night, they consume oxygen and release CO2 (meaning, even more CO2 in the water column). As a result, the CO2 you're injecting is simply being wasted, at best, or causing your fish to struggle to breathe and/or suffer from hypoxia, at worst. An easy way to see if your fish are struggling is to see if they're "snorkeling" at the surface. If so, they may be having trouble respiring.

Having said that, I run my setup 24x7. Although I do have a solenoid, I have noted two issues with putting it on a timer. 1) I see a pH swing overnight of 6.8 to 7.6. I don't like seeing that much of a swing in an 8-hour time period and it seems that's a greater danger than the likelihood of hypoxia. 2) The rate of injection (based on bubble count) fluctuates too much after restarting the CO2 flow and I find myself messing with the needle valve all the time. I have an Aquatek regulator that I've had other minor issues with and this is likely a result of a lower-quality needle valve. In any event, the system works fine if it just stays on, so I let it run all the time.

In contrast, I do run an air stone at night so as to create additional surface movement (thus gassing off CO2). The point of the air stone is not to "add" air to the water; rather, I use one that creates larger bubbles which then create surface movement. You might accomplish the same thing by running a power head or additional filter at night that breaks the surface. Using this method, my pH remains relatively steady at about 6.8-7 (with the implication being that CO2 levels also remain fairly steady). As such, I'm comfortable with how I have mine setup.

Of course, all that CO2 you're injecting (and gassing off) at night is pretty much wasted. In theory, you could extend the life of a tank of CO2 by putting it on a timer (or even a pH controller). However, it costs me $14 to refill a 5-pound tank. So, it's not like we're talking a truckload of dollars here.

 

[Kristian Tombs]

I assume you mean a regulator with or without a solenoid so that you can connect the CO2 to a timer.

This setup is not strictly necessary. However, many people note that injecting CO2 during night hours may cause your levels to rise above a level your fish are comfortable with. This is a result of the fact that plants only use CO2 during photosynthesis. At night, they consume oxygen and release CO2 (meaning, even more CO2 in the water column). As a result, the CO2 you're injecting is simply being wasted, at best, or causing your fish to struggle to breathe and/or suffer from hypoxia, at worst. An easy way to see if your fish are struggling is to see if they're "snorkeling" at the surface. If so, they may be having trouble respiring.

Having said that, I run my setup 24x7. Although I do have a solenoid, I have noted two issues with putting it on a timer. 1) I see a pH swing overnight of 6.8 to 7.6. I don't like seeing that much of a swing in an 8-hour time period and it seems that's a greater danger than the likelihood of hypoxia. 2) The rate of injection (based on bubble count) fluctuates too much after restarting the CO2 flow and I find myself messing with the needle valve all the time. I have an Aquatek regulator that I've had other minor issues with and this is likely a result of a lower-quality needle valve. In any event, the system works fine if it just stays on, so I let it run all the time.

In contrast, I do run an air stone at night so as to create additional surface movement (thus gassing off CO2). The point of the air stone is not to "add" air to the water; rather, I use one that creates larger bubbles which then create surface movement. You might accomplish the same thing by running a power head or additional filter at night that breaks the surface. Using this method, my pH remains relatively steady at about 6.8-7 (with the implication being that CO2 levels also remain fairly steady). As such, I'm comfortable with how I have mine setup.

Of course, all that CO2 you're injecting (and gassing off) at night is pretty much wasted. In theory, you could extend the life of a tank of CO2 by putting it on a timer (or even a pH controller). However, it costs me $14 to refill a 5-pound tank. So, it's not like we're talking a truckload of dollars here.

My idea was decreasing the speed of my spray bar during the day while running the co2 to allow more co2 for plants to utilise and at night to increase the speed at the spray bar to provide more oxygen for the fish and gas off more co2

 

[sodbuster95]

My idea was decreasing the speed of my spray bar during the day while running the co2 to allow more co2 for plants to utilise and at night to increase the speed at the spray bar to provide more oxygen for the fish and gas off more co2

I went with the airstone for ease. My timer is one of those plug strips where the timer alternates which plugs are active. I plug the light into one and the airpump into the other. So, when the lights are on, the air pump is off and vice versa.

Of course, your system should work fine, too. Monitor the CO2 levels for a while at various times (I.E., morning, mid-day, and night). If everything stays in a good range, then stick with it.

 

[Kristian Tombs]

I went with the airstone for ease. My timer is one of those plug strips where the timer alternates which plugs are active. I plug the light into one and the airpump into the other. So, when the lights are on, the air pump is off and vice versa.

Of course, your system should work fine, too. Monitor the CO2 levels for a while at various times (I.E., morning, mid-day, and night). If everything stays in a good range, then stick with it.

Okey I should probably set it up first before I worry about timings and stuff. Can you help me discuss essentials I already have an Idea but just to be sure

 

[20cc]

i tried it once and woke up to all my fish at the surface , theres debate whether to run co2 at night or not , to me you can do it either way just make sure your bubble count is right on point

 

[sodbuster95]

Okey I should probably set it up first before I worry about timings and stuff. Can you help me discuss essentials I already have an Idea but just to be sure

Getting setup isn't really all that hard. At it's absolute basic, all you need is a CO2 source and some way to get it in the water. There are plenty of ways to do a home-brew setup involving yeast and such that can be very inexpensive. Of course, going that route frequently means more work. I looked at that option, but decided I didn't want to mess with it.

So, assuming you want a pressurized system (I.E., a tank), you'll need the tank, a regulator, hose, and a diffuser (if you're going to use a spray bar, that will take the place of the diffuser). You may also want to use a bubble counter so you have more ready control of the rate of injection.

As far as the tank is concerned, I'd suggest looking around at fire equipment stores or even craigslist to see if you can find a cheap used one. If you do, make sure the hydrostatic test date is good. Once it's past the date, most (all) places will not refill until it's retested. Saving 20 bucks on a used tank doesn't do you much good if you immediately have to spend 20-30 for the hydro test. You can find new 5-pound tanks on Amazon for about $60. A 10-pound tank is a better value if you have room as it costs only a bit more to fill, but you get (almost) twice as much gas.

Another option is a paintball tank. There are several adapters available that will let you use a paintball tank on a "regular" regulator. This is a cheap way to get started and, by using an adapter, gives you the option to upgrade to a full-sized tank later. Aquatek makes a regulator specifically for paintball tanks, but I wouldn't recommend it simply as they cost about $90 and lock you into using only paintball tanks. In contrast, the adapter for using a standard regulator runs about $10. I keep a full paintball tank and adapter as a standby replacement for my 5-pound tank when it's getting refilled.

A final option is to get a Fluval CO2 cartridge system. Again, these are a cheaper way to get into CO2, but cost more in the long run. A 3-pack of 88 gram CO2 cartridges is about $30. At 30-60 bubbles per second of injection, one cartridge will probably last about a month. However, your rate of injection will vary depending on a number of factors, particularly water surface movement. For example, bio-wheel filters will dramatically impact how much CO2 you need to use. When I had a bio-wheel in use, my rate of injection to maintain a pH of 6.8 was 180 BPS. When I replaced the bio-wheel with a canister, that went down to 60. More surface movement equals more gas dissipating into the atmosphere.

As far as regulators are concerned, there are all kinds of options. Many people advise building your own. While I'm sure that would get you a good regulator (if you know what you're doing), I choose to get a manufactured one. Browse this forum and the web and find something that gets good reviews. I purchased an Aquatek Premium and am satisfied with it, but it does have some issues. However, it only cost me about $90 via Amazon, so it wasn't extremely expensive and it works.

Once your system is setup, you need to monitor the rate of injection. The easiest way to do that is to monitor the KH and pH. While this is not a precise measurement of CO2 levels, it is an acceptable approximation. For example, in my 29 gallon tank, I keep my KH at 5 and my pH at 6.8. This results in a CO2 level of approximately 24. A level between 15-30 is what you're after. There are chart available that give you the measurements or, if you do a search, you can come up with the formula for yourself. I have an Excel spreadsheet that automatically shows my CO2 levels based on the KH and pH. You can also use the checkers that are sold for the purpose that incorporate a 4 KH solution and (basically) pH fluid. The color tells you whether you have enough CO2 or not.

Like everything with fish tanks, there's no set-in-stone numbers here. Your ultimate goal is to find a balance between light, ferts, and CO2. You'll only get that through experimentation.

 

[Richardwm]

I don't use a solenoid but it's kinda a hassle to make sure I turn off the co2 in the morning a solenoid would have deff been better.