Ph adjustment

Jeranken

Hello one and all: I am setting up a wood boiler to heat my home and garage with hot water. My well water has a ph of 6.6, a little on the acid side, and I need to raise it somewhere between 8-9 I am told for for the good of my boiler and pipes. My system is roughly 325 gallons, and I have granular sodium hydroxide. How much sodium hydroxide will it take to bring 325 gallons of 6.6 ph h20 into the 8-9 ph range? Boiler temp will be in the 180-200 degree range.

Jamie Hall

Without knowing the rest of the chemical composition of your water that can't be answered, unfortunately. Natural water has what is referred to as "buffering" capacity, which means that there are other chemicals in it which act to stabilise the pH -- and unless you test for that, you have no way of knowing how much capacity is there.

Your best bet, if you really want to use sodium hydroxide, is to take a gallon or so of your well water and add a little at a time and test the pH after each addition.

The resulting pH will not be particularly stable.

A better bet is slaked lime, which is much more stable -- and MUCH less dangerous to handle.

hot_rod

Is it an open system, or closed pressurized?

Did you check hardness or TDS? There are hydronic additives that will buffer ph, lock up some hardness and scavenge O2.

If it is an open system they have chemicals for those also, mostly O2 scavengers.

Robert_25

Most outdoor wood boiler dealers will have the proper additives in stock to treat a system like this. Controlling the pH is important, but you need the proper corrosion inhibitors as well.

If you want to use the material you have and at least get the pH adjusted, I think Jamie's suggestion of a "bench test" is the best approach.

Jamie Hall

One more point. I mentioned, but perhaps not sufficiently forcefully, that sodium hydroxide is a very hazardous substance to work with. Even for a bench test, you must wear appropriate gloves with long sleeves, an chemical proof apron or lab. coat, and at least splash proof eyewear under a face shield. If it is powdered form, you must also use a respirator.

There is a reason the Mafia used to use either it or quicklime to deal with unwanted individuals...

Jeranken

Gentlemen I thank you very much for your responses to the question I posted. Jamie’s solution verified my own suspicion of how to calculate dosage. I well know the danger involved with using caustic soda and have used it frequently at work for decades. I do not know readily where to find slaked Lyme. Thanks again Jay

HomerJSmith

KOH would probably be a better choice. You can get that from Amazon.