Questions on PH and KH with reference to http://www.csd.net

[SleepyAries]

hi guys, mind i ask some questions on PH n KH thing ?

searching through the sites gives mi quite a lot of informations, but i'm still having some trouble understanding over this PH and KH thing.

The "Chuck"'s site has gave mi a great idea on how to measure the amount of CO2 in my tank. however, i'm not sure on how to interpret the table. eg, its says if yr CO2 level falls inside the YELLOW zone, ie, above 25, it might be harmful to yr fishes, and the optimum CO2 ppm would be 10-25 rite ? then how come some of the discussion in here talks abt increasing the CO2 to 30ppm ?

next,from reading around, i understand the PH could be adjusted by playing with the amount of CO2 u inject into the tank rite ? will the KH changes too if u play with yr CO2 injection ? eg: my tank reading gives a PH of 6.5, and KH 4 degress, the calculation in chucks site tells mi my CO2 is 37.9ppm, which the tables says it's way too high...thus, i reduce my CO2 injection from 3bps, to 2bps, to increase my PH value, but will my KH changes too ?
(think tat's y my malayan shrimps are dying off 1 by 1 everyday...)



also, say i've change my CO2 injection rate, can i ask how long does it takes for the PH level to settle down before i can test for its PH level again ?

lastly, say a plant needs low PH and low KH, am i rite to assume under this 2 conditions below, the plants will be fine since the CO2 in both case is the same ???
conditon 1 : KH 1, PH 6.4, and the green CO2 square reads 12
condition 2 : KH 2.5, PH 6.8, and the green CO2 square reads 12 too ?


thanks.
J.J

[vinz]

1) 30ppm CO2. There are many opinions out there about CO2 levels. Some forumers have tried 30ppm and gotten good results. Usually, more light requires more CO2.

2) No. KH will not change if you adjust the CO2.

3) Try measuring the pH after a day.

4) If 12ppm is enough for the plant and the pH and KH is suitable, so why not?

Btw, just nick-picking... its pH not PH.

[PeterGwee]

Just to add...KH does not change with CO2 injection unless you have coral chips in your tank or canister filter...(acid condition cause by CO2 injection will dissolve some of the coral chips to raise the KH)

[Allen_1971]

1) There are many "recommended" ranges for CO2 levels... some recommend 20ppm others higher at 30ppm... however, aquaria is not an exact science, so these recommendations are just that... a recommendation. Its up to you to decide whats good for you.

2) Yes, CO2 injection is one way of manipulating your PH. During this process, the initial level of KH remains unchanged. When it comes to the level of CO2 in your tank, trust your fishes... if they aren't complaining, then its OK. Chucks calculator like many others presumes that the only buffers in your tank come from carbonates, and that the acidity comes from CO2... as such, this could be wrong. One common example is that we often have peat in our tanks which make the water more acidic.

3) how fast your tank responds to a change in injection depends on the size of your tank, the amount of plants, and the efficiency of your reactor/bell/atomizer... in short, no way to say for sure... try in a few hours, or to be safe the day after.

[SleepyAries]

roger...

thanks guys....
i'm now much clearer over pH and KH....

thanks vinz...(notice i use pH now...heee)[]

thanks PeterWee, my filter just contains ceramic rings, blue sponze and the whiet cotton sponge...=)

thanks allen...yr explanation are always soo sharp n clear...always enjoy the way u explains things as u r soo good with words...

J.J