CO2 Levels

[barramundi]

Hi All,

What is a good Co2 level for a planted tank.
Reading 2 different articals on the subject one says 15-35ppm and one says 10-25ppm? I have just purchased a pressuriesd CO2 system and its been running for 2 days now.
My Co2 level is at 35.8ppm for a 6x2x2 heavily planted tank.
Ph=6.8ppm
Kh53.7ppm
Gh53.7ppm
Nitrate6.4ppm
Lighting 3.7wpg
Are these paras good for a planted discus tank.

Thanks John

[ILLUSN]

i aim for a minimum of 30, everything else seems fine, do your self a favour and dont put discus in a planted tank

[Bad Inferno]

Do you have a ph controller ?
Have you calibrated it ?
why is Kh = Gh 53.7 ?
Is your kh naturally that high ?
were did you install the ph probe ?
how do you inject CO2 ?


I think co2 is great as long as the equipment is calibrated and provides a stable envronment. Do me a favour and check how long it takes the pH to retrun to 6.8 when you do a 25% wc.

[barramundi]

Hi Bad Inferno,

Sorry Ph should of been 6.5 my typing error.

I used a API kit to test Kh and Gh it's the 1st time i've used it.Just done a Kh test and it took 2 drops to turn it yellow though yesterday i put in 3 as was not sure how yellow it should turn.According to the sheet it's 35.8ppm for both Kh and Gh.

I have just done a 25% water change today at 12.30 just took another Ph reading at 3.00 and it's 6.5.

Don't have a Ph controller,i have set the Co2 up with a tube from the bottle to a bubble counter then to a glass diffuser which sits just underneath the intake of my canister filter and have it set at 1bps.

I have set up an air pump on a timer to come on at night.

I'm hoping i've set it up ok i'm keeping a eye on my water para's just in case i've not.I checked the Co2 level by Chucks site.

John

[DiscusDave]

I wouldn't use a PH controller, you want to maintain a constant CO2 level during the day, not a constant PH level. The current thinking in the planted tank world is PH drop due to CO2 injection is not harmfull to fish (you can inject too much CO2 and kill you fish though - but it's not due to acidity). Just run the CO2 on a timer about 30mins before lights on to lights out.

You absolutley must run air at night though to drive off the CO2. Plants use O2 at night, so you need to drive off the CO2 at the end of the light period. Otherwise you'll find the fish gasping at the surface in the morning. I have a planted tank with discus and they are happy and healthy and several pairs have formed and layed eggs etc, but I would recomend a lower CO2 concentration - 15ppm, and a corresponding lower light level, 2-3 watts per gallon.

[Bad Inferno]

Pressurised CO2 can provide HUGE pH swings in a matter of minutes. Be careful is all I can say. I did run some tests early on with my ability to trend the pH data every minute of the day. See web site

You need a more accurate kh reading. As you see .5 degree kh makes a huge difference in the co2 chart.

OK instead of filling the tube with 5ml fill it with 20 ml (4x) and you will increase your accuracy by 4 fold.

Drops mls KH Degrees
1 20 0.25
2 20 0.5
3 20 0.75
4 20 1
5 20 1.25
6 20 1.5
7 20 1.75
8 20 2
9 20 2.25
10 20 2.5
11 20 2.75
12 20 3
13 20 3.25
14 20 3.5
15 20 3.75
16 20 4