sum1 pleease explain!

[quitters]

ok im trying to work out my KH

3 drops and the water turns yellow, then it says to multiply the number of drops by 10. so is my KH 30? or do u guys all talk in dH?, which is 1.5?????

ok ooo i really need to know this. it says 20 - 80 mg (mine is 30) KH, is soft acidic water, but my ph went up to 7.5 from 7 is this because of me adding ammonia?

is 30 KH enough of a buffer? im so confused coz people say they dont have enough of a buffer and mention a figure like 1 - 3, but apparently we have really soft water here, so were those people talking in dH and what does that mean? sorry thanks for any help :S

 

[Fishyfanatic]

Which test kit are you using?

 

[quitters]

nutrafin KH/GH im testing with the KH

 

[BrianNY]

In my hardness test kits, 1 drop equals 1 degree dh. The buffering capacity of your water depends entirely on the KH. JMO but if you're already seeing pH drops then your water needs to be buffered. A handful of cc will safely and slowly do the job.

 

[quitters]

yeh thanks ill do that.

 

[jsoong]

Quitters, Oz, like Canada, measures things in metric (mg/l). Most people in this place, however, talk in dKH.

FYI, dKH = mg/l x 0.056

KH of 30 is low & has little buffering capacity, that's why you see pH swing with NH3. As stated before, you need to up the KH to prevent that

 

[CGGorman]

FYI...mg/l is the same as ppm.

 

[quitters]

thanks guys

ive added some crushed coral

if wood raises ph, it increases kH yes? or gH? like does it add buffer or just raise gH and pH?

thanks!

 

[Fishyfanatic]

Wood does not raise pH or hardness. Wood lowers those levels.

 

[quitters]

lol oops, i always think acidic is higher ph heh.

it doesnt lower kH though does it????!

 

[jsoong]

A simple way of thinking about KH & GH is this:

KH = carbonate/bicarbonate level.

GH = Ca & Mg levels.

KH is your buffer, GH is your hardness.

If you add baking soda (NaHCO3), you are only adding HCO3 ie KH. If you add crush coral (CaCO3), you are adding both Ca & CO3, so increasing both KH & GH.

Wood releases acids as it decompose (tannic acid mostly), so will lower pH. However, your buffer will actively binds with this acid, reducing the magnitude of pH drop. <This is the meaning of buffer - it "buffers" against changes in pH.> In theory, any added acid will consume buffer, so will reduce the KH. <This is the reason for pwc - to replenish your buffers before they are used up & you end up with a pH crash.>

However, with crush coral in the system, the KH will not change (much). The solution of CaCO3 is pH based, the lower the pH, the more it will dissolve. When you first add cc, some will dissolve in until equilibrium. As the HCO3 is used up in the water, the pH will start to drop, more cc will dissolve, bringing the KH back up, etc. Essentially, the cc is acting as a reservoir, keeping your KH stable. You won't see a KH/pH drop until the cc is all used up.

 

[quitters]

thanks heaps for that jsoong, ok last question!

wont a partial water change send things out of wack? ive added crushed coral to replace the need to raise the KH of new water every time i add it. but if the water in the tank has a higher KH due to the coral it will dilute everything couldnt that cause a ph crash?

OH do i not have to worry because in matching the ph of the new water to the tank's im matching the KH as well? but then why did i get coral? oh for the reservoir. man my local fish shop doesnt know jack. so does that mean i dont have to worry so much about how much coral i put in?

 

[jsoong]

When you are doctoring your water, pwc with plain tap will change your parameters. Compared with your tank with cc, plain tap has lower pH and KH. So adding plain tap water to your tank will dilute the KH and drop your pH. The magnitude of the pH drop depends on how much water you change out (but is less than a simple math average because of the effect of buffering). Most would agree that for 10% change or less, the pH change wouldn't matter much. Within a day or so, the cc will dissolve into the new water & bring everything back to equlibrium.

If you must do a big water change, you should doctor the water before adding to tank. Some people keep a bucket/barrel of aged water ready for this. <In your case, all your need is put some cc in the water a few days beforehand.> In an emergency, you can prepare water with matched pH & KH by using baking soda (but the GH won't be matched.)

And yes, the beauty of using cc to doctor the water is that it is easy & automatic. You don't have to calculate how much to add, etc. As long as you have an excess of solid cc, the system will always return to the equlibrium pH/KH automatically.

 

[quitters]

ok thank you man!