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Re: NaHCO3



Sungmin Hong writes:

> I decided to use r/o water to solve my high nitrate problem. My tab water 
has 
> about 16ppm of nitrate.
>  5 days has past since I started to use r/o water.
>  r/o water droped Nitrate to 4ppm, but it also drops pH and KH. especially, 
> pH drops to 5.5.
>  I'm using NaHCO3 for KH and pH buffer, and add about 2.4g per 30 gallon 
> everyday.
>  acctually, it's really effective, but only short term. it raise pH about 
0.6,
>  but ther pH recovers in several hours.
>  is there other sources that last longer?

The problem is how quickly the acids in your water react with the CO3- ions.  
After a while, the acidity will be reduced.  I am surprized that your pH is 
that low and wants to stay that way, but everywhere you go, tap water is 
different, and some folks have really unique conditions.  For long term 
stability, you might try Dolomite.  I am a big fan of this stuff, though 
others will say something else is better.  Dolomite is available crushed at a 
very low price, and adds both Ca and Mg to your water, which your plants will 
probably tolerate better than high levels of Na, which you are causing now.  
You can suspend a nylon sock or other "bag" of dolomite in your tank, wait 
for the pH and KH to rise to where you want it, then pull it out.  The only 
problem then will be to adjust the KH of change/replacement water.

Or maybe you are injecting more CO2 than you need, and reducing the flow rate 
might help.

Bob Dixon