Uses for pH increaser (sodium carbonate)
If you have a lot of pH increaser (soda ash, sal soda, washing soda, sodium carbonate) on hand and you don't want to use it in your pool anymore there are many household uses for it. One of my favorite is to pour 1/2 a cup down the kitchen sink then flush with hot water to keep the drain running clear.
Here are some links:
http://www.care2.com/channels/solutions/home/440
http://www.care2.com/channels/solutions/home/1498
http://www.thelaundrybasket.com/Our_...shing_sod.html
As Ben said, Borax will raise pH without raising your carbonate alkalinity.