pH below 7.6 tank crash

[40B Knasty]

Buy a bottle of Prime to detoxify chloramine and chlorine.
Get a bottle of Nite-Out ll to help add more beneficial bacteria to help process the ammonia.
It is fine to use old sand that is in the 6 month range. Any older it could be a ticking time bomb. It may not happen in one day, but a month down the road and then once more another month down the road. Same goes for live rock. It happens. So never rule that out if it was not rinsed well being put in a new tank that is just cycled. If someone got lucky with no issues with their sand or live rock. It is exactly what it is, lucky.
Sorry about your fish loss. Hopefully everything will balance out soon and you can get some new live stock to enjoy.

 

[laverda]

I was on city water so used 5 gallon drinking water from Walmart to use for water changes etc moved into my new house on my own well only thing I did different was I used 7 gallons of tap water to finish topping it off when filled the tank on Thursday night by Friday night all the fish died in a matter of an half and hour. As on now all my acans, nem, snails and zoas are fine and still can see pods swimming in the tank that I put in for the mandarin that's why I'm so confused as to what happened

The pH test that almost looks like apple juice came out of my well.

The greyish one came out of my fish tank 30 min ago

Well water should not contain chlorine or chlorimine, but may contain much higher levels of iron, lead, copper and other minerals