Okay, consider this a lesson learned. It all comes down to the packaging when a consumer is purchasing a commodity. In this case the commodity is sodium bicarbonate.
Last week the motor to the pool was finally repaired and I was able to get to work at bring the pool under control. In the 3 weeks it took for it to be fixed, the water had turned a decidedly fluorescent green, as you can see in this picture!
After testing the water, I found it measured very low on alkalinity, about 30 ppm when it should be over 120-150 ppm. I think the oak leaves must raise the acidity a lot because this happens every spring! Anyway, I guestimated I needed about 40 pounds of "alkalinity up" product to bring it up to the proper level. Having 10-11 pounds on hand, I visited Lowes and bought another 24 pounds. It sold in 12# boxes and averaged out to about $1.16/pound.
Knowing I could buy it in larger quantities than 12#, I called the local pool supply store. The largest they had was 10# and it averaged $1.60/pound. Yikes, it's going up!
But what is the "alkalinity up" product? It's just plain old sodium bicarbonate. Otherwise known as baking soda, like that Arm & Hammer box you put into the fridge. And how much does that cost at the grocery store? For a 1# Arm & Hammer is was $0.69, and if I went with the store brand it was just $0.59 a pound.
What this lesson for me really proves is that when a product is intended to be used on a pool (this also applies to boat owners), the price is automatically doubled. And the marketing and packaging is everything in pricing for a commodity. Meantime, next year I'll purchase it at the local super market!