Balancing KH w/o >GH?

[Mr Pleco]

The Petsmart in our area has this product on clearance sale? Do you think a bag or 2 inside the sump or canisiter would help raise my KH levels w/o raising GH or PH ? If it does how fast do you think it would raise PH? or should I just add sodium bicarbonate ? I prefer a more natural type of leaching , trying to avoid the PH rollercoaster...

http://www.seachem.com/products/product_pages/GrayCoast.html

 

[brianp]

This material contains considerable amounts of calcium and magnesium, which will increase the GH. KH will only be increased if one or more of these is/are complexed with carbonate. Since they describe this as "calcite", we know that the calcium is actually "calcium carbonate". The magnesium is probably "magnesium carbonate". You could achieve the same effect with dolomite....available at nurseries for pennies per pound.

 

[Mr Pleco]

This material contains considerable amounts of calcium and magnesium, which will increase the GH. KH will only be increased if one or more of these is/are complexed with carbonate. Since they describe this as "calcite", we know that the calcium is actually "calcium carbonate". The magnesium is probably "magnesium carbonate". You could achieve the same effect with dolomite....available at nurseries for pennies per pound.

Thank you for your reply

 

[Mr Pleco]

Looks like I'll be adding sodium bicarbonate to the sump today on the 150. trying to raise the KH by 2. So I will be adding about 6 teaspoons which should work.?? fingers crossed w/o affecting PH??...BTW my tank params took a dive this week after the introduction of a large piece of driftwood last week...bi weekly water changes and the ph and kh are still low.

Here's my test reults prior to the addition of the Bicarbonate:
150:
KH= or < 1
PH 6.0 to 6.2
GH = 10

My tap is

KH = 2-3
PH = 8.2
GH = 10

After additon of Bicarbonate I'm expecting

KH = 2-3
PH= 6.5
GH =10

Any thoughts or comments? teste results are from a Red Sea freshwater test kit..ictm

 

[brianp]

In my tanks, it is a given that there will be progressive acidifcation over time, due I think, primarily to CO2 + H2O forming carbonic acid. Of course, there are other factors as well. Basically, I use sodium bicarbonate to achieve the same objective as you, but am less technical in my approach. I simply determined empirically how much bicarb must be added on a weekly basis to keep the pH more or less stable, divided that amount in two and add one aliquot to the replacement water reservoir and the other aliquot midway through the week. For me, this works well.

 

[Mr Pleco]

So far all fish appear to be doing well!

PH is at 6.6
KH is at 4

 

[Mr Pleco]

Update PH, KH and other params are holding.

Here's the link I used for raising KH...seems to work..

http://dataguru.org/misc/aquarium/CalKH.asp?Gallons=150&KH=2&measure=0&Baking+Soda+%28Teaspoons%29=5.77&SKH=1&EKH=3&pHChange=0.00