Once you get the pool properly balanced in pH, Total Alkalinity (TA), Cyanuric Acid (CYA) and Calcium Hardness (CH), then your main expense will be adding chlorine regularly. You should seriously consider getting an automated chlorine system -- either a saltwater chlorine generator or for bleach or chlorinating liquid you can use
The Liquidator.
To add 4 ppm FC to 45,000 gallons will take 23 cups of 12.5% chlorinating liquid. It costs me $3.50 per gallon, but prices vary a lot around the country, so this would be about $5 and could be a daily cost if your pool uses 4 ppm FC per day. That's on the high side of usage and very much depends on how exposed your pool is to sunlight, whether it has an opaque pool cover, etc. Your actual usage could be half that. Clorox Regular bleach is 6% (actually, 6.2% "trade") so is about half the strength, but may be less than half the cost of chlorinating liquid in your area -- remember that it comes in 96 ounces, not 1 gallon, so you need to account for that when comparing costs.
You can use a higher CYA level, say around 60-70 ppm, and maintain a higher FC level of around 8 ppm and this may reduce your chlorine usage from the sunlight breakdown. However, the best way to cut down usage is using an opaque to UV pool cover, but that's a pain to put on and off unless you get an electric automatic "safety" cover (that's what I have, but my pool is only 16,000 gallons).
BBB stands for "bleach, borax, baking soda" and refers to using store-bought chemicals instead of pool-store chemicals. Unscented bleach is the same as chlorinating liquid from the pool store except that it is about half-strength (or less, depending on brand -- Clorox Regular is 6%). Borax can be used to raise the pH instead of using pH Up and has the advantage of not increasing TA as much. Baking soda is identical to Alkalinity Up to raise TA. However, once your pool water chemistry is balanced, you usually only have to add chlorine and occasionally add a little Muriatic Acid to keep the pH down and even more rarely add some baking soda to raise the TA -- this depends on the amount of aeration in the pool.
Personally, I prefer paying a little more for the chlorinating liquid from my local pool store as it is more convenient (less weight to carry) and they reuse the bottles which I return to them (they clean and refill them). Also, with an opaque pool cover, my chlorine usage is less than 1 ppm FC per day.
Richard
.The pool guy working on it now says its a 45,000 to 50,000 gal pool.All I know is it's BIG!My first of (im shure)many questions is how much does it cost (ballpark)for chemicals a month?What will I need too start with? Im not the kinda guy that just calls somone and then write the cheak!I want to learn how to do everything myself on a budget.I have reef tanks now so Im pretty familiar with testing water.