Can I safely raise my Cl to 35 with a vinyl liner without bleaching it?
Arm & Hammer Washing Soda = sodium carbonate (AKA soda ash)
20 Mule Team Borax = sodium tetraborate decahydrate.
Both raise pH; soda ash also raises alkalinity. Borax inhibits algae -- but you'd have to use over 12 boxes to get to that level. By the way, according to Walmart.com, borax is in stock in Lockport.
Regarding vacation, you have several options:
1. Raise CYA to 200+ ppm and chlorine to 35+ ppm. That will probably last till you get back. Not recommended, unless you are already nearly that high. If the 30 ppm above is the value from the K2006, this is not an option.
2. Raise the CYA to 50 ppm, and have your friend add 3/4 gallon of PLAIN 8.25% bleach every other day.
3. Raise the borates (from borax) level to 60+ ppm, put your filter on recirculate (circulate, but not filter) and add 1/2 quart of 60% polyquat when you leave, and 1/2 through your vacation. See www.poolsolutions.com/polyquat.html.
To raise your borax to 60+ ppm, you'll need to buy 10 boxes of borax and 3 gallons of muriatic acid. Add 4 boxes of borax SLOWLY through the skimmer with the pump on, and add the muriatic to the pool. Repeat. Then use the remaining 2 boxes of borax and gallon of muriatic to adjust the pH up or down, as needed. Leave the pump on for at least 4 hours after. Read the muriatic acid safe-handling page, linked in my signature, before adding the acid.
Can I safely raise my Cl to 35 with a vinyl liner without bleaching it?
I can't answer that absolutely: I've encountered liners that seemed to be bleached out at chlorine levels under 5 ppm. But, with a decent liner print (the liner can be OK, even if the inked print is not), FC=35 should not be a problem if CYA = 100+.
On the other hand, 35 ppm at CYA < 20 ppm probably WILL be a problem.
PoolDoc / Ben
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