optimum KH

[chua]

From the past questions posted in the forum, to obtain the desire CO2, we will need to know both the KH and the PH. But what is the optimum KH. Is it true that as long as you have the correct range of PH corresponding to that KH and your fishes and plants are also within that range of PH, it will not matter. As long as the KH is not less than 1.

Can anyone help.
Thks

[geoffrey]

The purpose of having at least some KH is to prevent pH swing between light on and off period. Keeping it at between 3~6 is ideal IMO. Doesn't harm even at 10.

[jacian]

There is no optimum KH. Depending on what kinds of plants you are keeping, the recommended level is between 3-4.

[Plantbrain]

I never knew there was ever an optimal KH or pH.
Plants want CO2, not a certain KH or pH.
These terms are only used to determine the CO2(the acid).

If you have less than 1-2KH then you have no buffer in the acid-base and then you have trouble using a pH scale to measure the acid. Keep both KH/GH above 3 or about 50ppm to prevent this(GH is for nutrients only(SO4, Ca++, Mg++) not CO2).

FWIW, if you consider many pH measurements made in soft waters such as Florida, Rio Negro, SEA etc have no buffer and are very pure, then how do you get an accurate pH reading? You need a special probe etc to do this but few researchers do this or have done this in the past. So do not trust everything you read about soft waters.

Plants can be found in both soft and hard waters. It's not where they necessarily WANT to grow, but just where they CAN grow. Optimizing plant growth is always what you find in nature. Keep that in mind before applying that notion.

See Claus's and my comments over the years on the APD about hard water. We independently say the same thing.

Regards,
Tom Barr

[FC]

IMO, KH level is not important as long as it is above 1 for ease and economical way of PH measurement. I keep it at 2. Smaller tank may need higher KH to provide buffer to peak & dips of PH.

Where the buffer came from is the one that is crucial. I find the CaCO3 source being safe and benificial.


Regards,

Freddy
www.killies.com

[chua]

From what i had read, the value of KH will not affect the PH swing. As long as it is above one, the PH swing will still be the same regardless of the KH.

This is where i read it from
http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm

Hence can i conclude that as long as the range of PH correspond to your KH is within the acceptable range of your fishes and plants, it does not matter.

Thks for all the help.