[SankenAquaticFoliage]

I am thinking about getting a co2 system for my tank but i still have a few questions. In my 29 gallon tank, mediumly planted and medium/high light, how much co2 should i be giving out? Like in bubbles per minute. Also, how long would a 20 oz paintball tank last?

 

[PlantedRich]

There are many, many things that will change the final answer to this. How many plants of what type is one but then much of the question will depend on your tank and operation. How you put the CO2 in will change how much stays in, how much water movement and top ripple will change how much stays. What type and what you have in the bubble counter will change the bubbles. how much is enough often depends on what type and how many fish because some will tolerate more than others.

But just as a safe place to start, many consider starting very slowly when you can be there to watch the fish and then over time slowly increase the amount until the fish begin to react badly or you reach the point you fell is correct for your tank.

Sorry. No firm answer that can really be true.

 

[SankenAquaticFoliage]

Should my pH change during this time? And what would you consider as "starting slow"?

 

[payluder]

You should get a Ph and Kh tester this will help you determine how much co2 you need in your tank. I use this calculator to help me get the right amount. Aquarium CO2 Calculator

 

[junglefowl]

Agreed that it depends on how much plants and what type of plants do you keep in the tank, also what method you're going to use to diffuse CO2 (reactor, diffuser...)

For 29gal tank, you can run 1-2bps (bubble per second), then watch how the plants grow and increase if needed.

Better invest in CO2 indicator/drop checker, it can help determine how much CO2 you have in the tank.

 

[PlantedRich]

One or two bubbles per second is usually a safe place to start but from there, you are likely to find lots of variables and hangups in the way we measure and calculate things. Drop checkers are one of the more common ways to go and seem to work for many. But that does take some knowledge of what's happening. It is a more or less calculation of how much the PH has changed and you have to be able to judge colors just as in judging the colors in many of the water tests. Not a precise thing as somethin as simple as the lighting can change the way we see colors. The hangup with measuring the PH and KH and then going to a chart is there are several things that can skew the readings. One is getting a good PH and KH reading from hobby level test kits. Many will agree that it is a shot but not a real good one? Second is that the PH&KH charts often assume that there are no other minerals in the water when we know that most water does have those other minerals to mess with the final answer. The chart method does not work for me as it would lead me to believe my fish are living and breeding in 80PPM CO2 when normally 30 PPM is suggested as safe! But then the calculation of that 80 PPM depends on the accuracy of my testing so I throw that answer out.
I used a drop checker, tried the chart and kept increasing the CO2 until my fish began to act strange. That's why we want to adjust it when we can be there to watch for trouble as there is no firm way to say what is enough. Too much WILL kill your fish and that is my main "test". If the fish are okay, I may increase but when they say, I back it off.

 

[lksdrinker]

dont worry so much about how many bubbles per second, or how many ppm of co2 you have. Its nearly impossible to compare one setup to another (how big is my one bubble per second compared to yours? what psi am I running compared to you etc etc etc). Drop checkers are good tools to use. You're aiming for a rough drop in ph of 1 point to occur within an hour or so of the lights and co2 being on. Very general vague guideline here. I think the best thing to do is focus on your tank and no one elses. Start slow meaning inject very little co2 to begin with. Maybe 1 bps. Monitor your fish over time and keep increasing the rate of co2 (and allow time for things to stabilize). maybe on day 2 you nudge the needle valve to increase to 2 bps. Keep doing this slowly and keep a real close eye on your fish. Once you get to a point where the fish are heading to the surface and gasping for air then you've found how much is too much for this setup and you can back off the co2 a tiny bit. Now you should be injecting just enough so you dont harm your livestock.