Is my math correct in that I will need almost 47 pounds of 20 mule team borax to get my 12500 gallons up to your recommended 50 ppm. 60 Oz's by weight per 1000 gal X 12.5 gal = 750 Oz's. divided that by 16 Oz's per pound is 46.87 pounds??
Yes, It comes in 76 oz boxes (4.75 lb.) and costs about $3 a box at grocery stores, walmart, target, etc. You will need a bit less than 10 boxes for the initial dosing.
This is the box you are looking for at the store.
You will also need about three gallons of 20 baum (31%) muriatic acid, which is usually abut $5 a gallon or less.
You should also pick up a tube of LaMotte Borate test strips for about $10. They are far superior to any other borate strips I have used, MUCH easier than the expen$ive Proteam Borate drop test kit, and are precise enough to keep you in the 30-50 ppm 'sweet spot' for borates in a chlorine pool.
When the borate levels drop to 30 ppm bump them back up to 50 ppm with borax and acid. I need to do this about every 1.5 years in my pool so far.
I hope this stuff is cheap.
It is.
I need a little more help in understanding what amount of CYA I need to have in my pool. From reading threads in this forum it seems like the more CYA you have the higher amount of free chlorine you need to have also.
While that is true the amount of chlorine actually consumed tends to stay the same or actually go down a bit. In very hot, sunny climates CYA as high as 80 ppm is not necessarily a bad thing, as long as adjustments to the chlorine levels are made to compensate. Also, there is some limited evidence that CYA levels above about 70 ppm actually have a secondary shielding effect against UV that cannot be explained by the chemistry alone and might be an actual 'sunscreen" effect that increases with depth. Chemgeek can explain more about this than I can.
Consider that pool services that use gas chlorination in plaster pools routinely use CYA levels of around 150 ppm to maintain a workable FC level for a week between chlorinations and that this method is very successful at maintaining a clear pool.
Do I need to add any poly quate 60 algaecide?
Not with the borates, It wouldn't hurt but is an unneeded expense, IMHO. Also if you are going to shock be aware that polyquat does have an effect on chlorine levels. IF, after adding borates, you still have a problem with algae then a weekly dose of polyquat would be a second level of "insurance" but I do not think you will need it.
When I return the future times I will shock in the evening when the suns low in the sky. Does the shock need to get the water back up to the 25-30 ppm level again each time I do that?
I purchased 4 lbs of CYA at my local pool store 2 weeks ago but have not used any so far. My 32ppm CYA has come from using Trichlor for six weeks.
With a CYA of 30 ppm (I know of no way you could get 32 ppm reading from a
Taylor kit, it does not have that kind of precision!) you only need to shock to about 15 ppm. This chart should be helpful to you in where to maintain your chlorine and where to shock. Too high a chlorine level in a vinyl pool could cause bleaching of your liner!:eek: