Co2

[TnMark]

My tank has a PH of 7.1 and GH of 11. According to the charts I see, that means the CO2 is approximately 25-30. Isn't this the optimal CO2 for a planted tank with fish. Is there an advantage to added CO2? If I increase the CO2 by adding, wouldn't that cause problems for the fish?

[Richer]

GH? Are you sure you are not measuring KH? As far as I know, CO2 charts only work off of KH and pH.

Assuming you are referring to KH, then yes, your CO2 concentration is fine. I would keep your levels at where they are. CO2 levels tend to get harmful when they go past the 35ppm mark.

On that note, why do you want to raise your CO2 levels?

-Richer

[TnMark]

Oops, I was looking at GH. My KH is 6 which means my CO2 is about 14. I only wanted to raise it if my levels were too low to grow plants adequately.

[Richer]

14 is fine... you still have room to play around with. My CO2 levels are generally in the 20ppm range.

-Richer

[TnMark]

Thanks.

[Bremer]

Unless I misread your message, you are not currently adding Co2, right? If not, then I do not believe the 14 ppm figure. Ambient Co2 levels are under 5 ppm. If you aren't currently adding Co2, something is affecting you ph or kh readings because your water should not have 14 ppm co2 on its own.

If you are adding Co2 and the question is to add more, than just ignore me. ;-)

[Richer]

Oh, you have a point, I wasn't reading carefully enough. If you are using something to lower pH (peat, chemicals, etc.) then the table doesn't work. The table only works if you are not using anything in your water that will lower pH.

-Richer

[TnMark]

The info I got was from the tables that are publisher for PH/KH/CO2. 14 was the number in the table if PH is 7.1 and KH is 6. I am not doing anything to change PH except aging the water in a holding tank prior to adding it to the fish/plant tank. The aging isn't changing the parameters much anyhow. Tap water here is PH 7.2, GH 11, KH 6 no ammonia, nitrates or nitrites.

I am using 260 watts of compact flourescent in this 135 gallon tank and my plants (for now anachris, foxtail and bacopa) are all growing like weeds. (I'm cutting about 8 inches every 2-3 days).

My question was because I was considering adding more plants that said need additional CO2 added. With the expense of my new tank I can't afford a CO2 system now. I am pretty uncomfortable with the DIY stuff, especially with the number of bottles I would need for a tank this size. Do you think I could grow these more demanding plants with the CO2 level in the water, or should I stick to the less demanding ones?

Thanks