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KH = 0?

6K views 8 replies 6 participants last post by  Momotaro 
#1 ·
How can I raise my KH without messing up my ability to use the CO2 chart? My tap water has a KH of 2. As days pass my KH goes to zero, don't know why. 50% PWCs Sunday and Wednesdays are not keeping the KH much over zero. The only way I know to raise it is buffer and everything I read says do not buffer. What can I do?

David
 
#2 ·
The message is "do not buffer with phosphates". You may use calcium carbonate to raise your GH and KH. You may also use sodium bicarbonate, AKA baking soda, to raise kh only. These 2 methods will not interfere with the kh chart. There are probably a few other methods that I'm not completely aware of but the 2 methods mentioned above are the most common. :wink:

Marcel
 
#3 ·
You did not say what your gH is but I'm betting it's also low. Do you have a water softener in the house? If so use water that is not softened. Otherwise I recommend the use of Calcium Carbonate to raise both gH and kH. Two teaspoons will raise gH and kH 4 points in 50 liters of water.
 
#4 ·
Thanks for the input.

My GH = 6. The KK used to be 3 and the GH 9. I don't know what has happened. All of my current readings are as follows.

GH = 6
KH = 0
NO2 = <.3mgl
NO3= 3ppm
NH3 = 0
PH = 6.6 on my monitor or 7.2 by my test kit.
Phosphate = 3mgl

Overdosed Phosphate at last WC. Probably contributing to my hair algae problems.

The low KH and NO3 probably explain why my plants haven't been growing. Also contributing to the algae.

I'm ordering calibration liquid for my Milwakee PH monitor and will check it. It was fine in March. Will try another PH kit tomarrow.

I'm using Potasium Nitrate, Mono Potassium Phosphates and Potassium Sulfate to dose my nitrates, Phosphates and potassium. Could they be affecting my KH?

David
 
#5 ·
My water out of the tap is pH 7.0, KH 1 or less, GH 2. I'm setting up my first planted tank, low light, but wanted the option to inject CO2, so went with Onyx sand over Flourite. That raised the values to KH 4 and GH 5. Only thing is, I've heard after a time the effect from the Onyx lessens. It would be nice if it had enough stability to prevent me from having to dose regularly for hardness. We'll see what happens.

James
 
#8 ·
If you read the information that goes along with Chuck Gadd's CO2 chart you will see that adding crushed coral might not be the best way to raise your KH.

There is on case I've seen where the addition of CO2 resulted in an increase in KH. This can happen when you have something in the tank that dissolves carbonate into the water. Seashells, crushed coral, and many gravels and rocks will do this. With the addition of CO2, the water turns more acidic, which will increase the dissolving of the minerals. It appears that increasing CO2 raises the KH, which isn't really the case. The dissolving minerals raise the KH, and the increase in KH results in an increase in pH. In a system using a pH probe and controller to regulate CO2 levels, this can have fatal consequences, since the pH controller will keep trying to lower the pH, but as more CO2 is dissolved, it lowers the pH, which raises the KH, which raises the pH. So you now have more CO2, but the same pH. So the controller adds even MORE co2. And it will keep going. So it's important to know your KH whenever using pH to judge CO2 levels.
I know for a fact that David is using a pH controller. I don't want to see him have a problem.

David, here is a link so you can read the article in it's entirety.

http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm


Mike
 
#9 ·
David,
I spoke to a gentleman over at Milwaukee about my pH monitor's probe a month ago. It was acting a bit wonky. He told me the probe might be contaminated. You might want to try and decontaminate it before you recalibrate. Here's what you do:
Make a solution of 1 part rubbing alcohol and 1 part RO or bottled drinking water-NOT tap water. Gently swish the probe in the solution for no more than two minutes. After swishing you can rinse the probe in tap water ( I rinsed in RO). That should decontaminate the probe. Then you can recalibrate.
Give it a try.

Mike
 
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