kh tester

[cees]

As far as I know, you can't have hard acid water

1 liter of water, a hand full of calcium nitrate, a dose of concentrated nitric acid and you have very hard, very acidic water

Sorry Pegasus, just couldn't resist.

And it's true, when it's fish and/or aquarium related you either find soft-acidic water or hard-alkaline water

[Derek]

John1 says:

Rob

I think you err with both.

According to my literature 1dGH or kH = 17.9 p.p.m.

Sorry to no doubt bore everyone with technical details but the problem is no one is defining the units they are talking about:

for example 17.9ppm is meaningless if you don't say what it is ppm of.

1GH is defined as the "hardness" of a solution when 10mg of CaO is dissolved in 1 litre of water.

The Molecular Weight (MW) of CaO is 56

Therefore 10/56 = 0.179millimolar.

However most kits give there answer in eqivalents of CaCO3

The MW of CaCO3 is 100.

Therefore you would need 17.9mg/l (17.9ppm) of CaCO3 to produce an "equivalent" hardness to a 10mg/l solution of CaO

Lets say you do a measurement of GH and get an answer of 1GH. That does not mean you have 17.9 ppm CaCO3. What it is saying is that the total net concentration of substances contributing to the hardness is "EQUIVALENT" to that provided by 17.9mg/l of CaCO3 or 10mg/l CaO.

Just saw your reply Cees while I was writing mine. That was what I suspected.

So if anyone has any buffering system in their aquarium other than just carbonates (i.e. using phosphate buffers to alter the pH) then these tests are pretty useless or at least misleading.

[Pegasus]

Hi all,

Cees said,

Sorry Pegasus, just couldn't resist.

And it's true, when it's fish and/or aquarium related you either find soft-acidic water or hard-alkaline water

Glad you added that bit. Aquarium water is my main concern

Hey John,

Now if you or I were an "Average" fishkeeper, would the last several posts "encourage" you to keep fish, or make you think twice about getting involved. This was one of the points I was trying to explain in my previous post :)

Should this topic not be in the "Technical" section ??

Or perhaps we need a "Water Chemistry" section

Happy Days,

Bill.

[Rob]

Rob

I think you err with both.

According to my literature 1dGH or kH = 17.9 p.p.m.

In case you are interested, here are some facts.

dGH = dKH + PH

GH = Total Hardness

KH = Carbonate Hardness

PH = Permanent Hardness

John

Now that I'm home with the reference infront of me (rather than relying on the grey matter) yes you're correct John re: total, carbonate and permanent hardness.

As for the how many ppm to a degree I did site the reference I used but as other people have pointed out my just saying ppm without refering to ppm of what is meaningless - is it ppm CO3(2-), some sort of CaCO3 equivalent, I don't know, the reference didn't say - could be the happy occurence where we're both right.

[john1]

Hi everyone

Lucky we are a happy bunch of people. Everyone gracefully excepting the other ones opinion. Nobody is perfect. Execpt me that is. HE HE.

A forum is here to lern, exchange ideas, have a bit of fun and also pass the time. Keep up the aggreeing/disagreeing,... it's fun.

I'm not a spring chicken anymore. My eyesight is not what it used to be. So I ivested in an electronic pH meter. Fast and accurate. Gives me more time to enjoy my overfed fish.

Greeting to all of you

John

[Pegasus]

Hi John,

We seem to have similar probs, and similar answers. he he.

I'm not a spring chicken anymore. My eyesight is not what it used to be. So I ivested in an electronic pH meter. Fast and accurate. Gives me more time to enjoy my overfed fish.