tank emergency !!!!!

[S-B]

danny zubot
The 40g and the new water I just mixed up both have such a low PH , is
doesn't even register/match any color on the chart .
I was going to swap out 10g of old from the 40g with 10g of newly mixed water in hopes this would help bring the PH up some . But when I test both
waters .....the PH is realy low . So to make sure my test kit was ok , I tested water from a 20g I have , and that water tested PH 8.2

So now I'm thinking , maybe I should remove 10g from my 40g and replace it with 10g from my 20g that tested ok ?

do you two think that is a wise idea or not ?
btw .....there is just sand in my 20g right now , as I've given away the crab and live rock I had in it .