Your ph is dangerously low if there is a chance that it may be as low as 6.5. Getting the ph up is your #1 priority right now! You cannot wait for aeration to bring it up. You need to add some 20 Mule Team Borax ASAP and get this ph up quickly. (Some test kits only register to 6.8 so sometimes a reading of 6.8 is actually much lower. Especially since you got another place that read it as 6.5.) Any ph below 7.0 is acidic and can damage your pool. Get some Borax in there!
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