art_b

After using DIY CO2 for quite a while, I decided to spend money on a CO2 bottle and a Tunze regulator. So far so good. Because I don't have the discipline to wake up at the same time each morning to turn on CO2, I decided to run CO2 for 24/7.

My KH is 3 and my PH during the day is 6.8. Before the lights turn on in the morning, my PH is 6.6. So using the CO2/PH chart my CO2 is 22 ppm during the day and 36 at night. I get around 40 bubbles per minute on my bubble counter.

My tap water is KH 1 and PH 7.4. The output of my filter is below the water line so there is little surface turbulence. I was thinking of raising my KH to 4 and CO2 to 30 ppm during the day, and buy a solenoid and timer to automatically shut down CO2 at night.

My questions are:

1. If I shut off CO2 at night, what happens to CO2 already in the water ? Will the CO2 eventually dissipate or escape from the surface ? Will my PH go up to 7.4 again ? Or will the CO2 be retained over the course of the evening ?

2. When I turn on CO2 in the morning, how long will it take to reach the desired ppm levels ? Should I turn CO2 on an hour or two before the lights go on ?

3. Or, should I just raise my KH 4 to and increase my bubble rate to reach 30 ppm CO2 during the day, and just leave it 24/7 ?

medicTHREE

1) It will dissipate, and quicker than you'd think, but your plants put out co2 at night as well. My guess is by the time your lights turn on, the pH will be back to 7.4. This is irrelevant though, as co2 induced pH swings are not harmful to fish(co2 is the problem, not the pH) as the GH and KH stay constant.

2) It depends on your method of diffusion and your water movenment in your tank. In a well diffused, well circulated tank with no dead spots, it will reach 30ppm in as little as 20 minutes. Most tanks need 1 to 2 hours for it to get there.

3) There is no reason to leave it on all the time, but you can. Just be very diligent and watch your fish. You need to watch for signs of distress.

Aquaticz

Hi,
I am also new to C02 as I started in mid Decemnber. I was coached by a guy that knows his stuff. At one time a moderator here. He suggested I get a Hanna PH meter and use the KH-C02 chart.
In doing so I have stabilized the C02 to an optimum level of 30 ppm. I keep it on 24/7. I was told not to turn it off, so I haven't. When the lights come on I am at the optimum amount of C02 which disapates throughout the day.

I use an Eheim Cannister filter as the reactor & it works quite well. In addition I added a power head for even more circulation.............bye ... bye .. BBA


Hope this helps

bosmahe1

I personally like running my CO2 24/7. I have just enough surface turbulence to avoid surface scum build up. Since I run it 24/7 I am able to run the CO2 a bubble rate of about 1.5 bps and have the ppm at ideal levels when the lights turn on at noon. I use one 20 OZ paintball cylinder per month on a 46 gallon tank with a 4x39 watt T5HO light fixture running all 4 bulbs running 5 hours out of a 10 hour lighting period. I do have a solenoid but don't use it. I find it easier to keep things stable without it and the additional CO2 cost is very minimal.

I think people that use a solenoid to shut off the CO2 at night run their bubble rate higher and start the CO2 flow an hour or two earlier than the lights kick on so they can "catch up" to the optimal CO2 levels by the time the lights turn on.

If you have a solenoid already, you might as well give it a try. I think most people prefer to use a solenoid, thinking that it is easier on the fish if CO2 is not applied when the plants aren't photosynthesizing. Also, the thought is that not running CO2 at night saves money by using less CO2 gas.

If you don't have the solenoid yet, you might want to try 24/7. I think you can keep the bubble rate low like you are now and still get a 30 ppm level. I doubt that you can over gas your fish at that level. I never have. As far as cost savings, you don't need to spend money on the solenoid, brass fittings and additional timer thus off setting any cost savings on gas.

medicTHREE

No need to run it at a higher bps... If you have it at optimal levels, with the same plant load, why would you need to run it higher to keep it there? Sure, when you turn it off you need to turn it on before lights come on, but you can also turn it OFF before lights go off.


There is no logical explanation how you can keep it at 30 ppm with lower bps. Yes, you are injecting at night when it is not being used, but only so much can accumulate before your fish are harmed. SO either it is spiking rather high, you have more surface exchange than you think, or you are not at 30 ppm all the time.

Simply put, if you were spiking high enough at night to make it so you could run with less bpm during the 24 hour period and maintain 30 ppm during lights on, you would be dangerously high. Therefor you are basically running at what others could run without running it all night long.

You could easily run that 1.5 bps starting an hour before lights on till about an hour before lights off and keep your 30 ppm too.

bosmahe1

If you balance surface movement with the bubble rate, you don't need to worry about spikes at 1.5 bps. I use a 4kh drop checker to monitor CO2 levels. Unfortunately, a drop checker is rather slow to respond to co2 levels so, for me it's easier to run it 24/7. I see that nice lime green color in the morning. When I used the solenoid, it was blue half of the day so, I really doubt that CO2 was at 30 ppm when the lights turned on at noon. I turned on the co2 at 10:00 am. And yes, I did turn off CO2 an hour before lights out and it save me money, $2.50 per month.

I don't understand why some people using solenoids think that's the only way to do it. There's always more than one way to do things properly, even in this hobby.

medicTHREE

I don't even use CO2 anymore, so don't say that. What I am saying is that there is no reason to run it all night.

You said it yourself, drop checkers are very slow to respond, so just because the drop checker hadn't changed color does not mean you were at 30 ppm. Were you having problems with growth or algae? Our plants and fish will tell us when there is a problem long before any equipment will.

Drop checkers are dependent on many things, position in tank, flow, age of solution, method of co2 dispersion, etc.

bosmahe1

My tank has minimal algae, plants are growing great, never ever saw fish gasping at the surface so, I don't see a need to use a solenoid and timer. I like the simpler setup. So to me that's all of the logic that's needed.

By the way, I never discredited folks using solenoids, I just think that it's not the only "logical" way to do it.

medicTHREE

That is great, but that doesn't refute the things you stated as fact. That is my problem with your argument, and has been all along.

You assume that because you run it 24/7 you are able to run it at a lower BPS than if you ran it only when lights were on. I do not believe this to be a fair assumption.

Personally choices and opinions are great, but should not be delivered as anything but that. There are too many missing pieces in this hobby to make vast generalizations based on singular readings and assumption.

bosmahe1

I think you need to re read my original post. I thought I made it clear that, that was an alternative observation, I didn't imply what I stated was fact. My opinion is that it can be done properly without a solenoid. I think I have read so many cases where people run co2 at 3 to 5 bps and not on particularly large tanks so, maybe that's reason for my remark about needing to play catch up for optimum co2 levels when the lights are on.