Water PH issue

[Qwertyl]

The tap water PH where I live is just over 8.0 so I’m using PH down. When I let the water sit in the reservoir I notice the PH increase by 0.3-0.4 per day. I measure the PH both from the top and from the bottom tube so it is not due to bad mixing of the water. Is this normal or is my PH-down just shit?

 

[myke]

Normal,nothing in the water for the pH down to grab.I maybe wrong but after you add food to the water it seams to stay.

 

[Qwertyl]

Normal,nothing in the water for the pH down to grab.I maybe wrong but after you add food to the water it seams to stay.

I do add food when I go away a few days and need automatic feeding but the PH keeps going up. This is really where it causes issues due to the discrepancy between the waters natural PH over 8 and the needed ph between 6 and 7.

 

[myke]

I do add food when I go away a few days and need automatic feeding but the PH keeps going up. This is really where it causes issues due to the discrepancy between the waters natural PH over 8 and the needed ph between 6 and 7.

Do u have an airstone in the res?A fella here was helping me awhile back.We tried 1.5ml per 5 gallon of pH up im my solution and that seamed to stabilized the ph.

 

[Qwertyl]

Do u have an airstone in the res?A fella here was helping me awhile back.We tried 1.5ml per 5 gallon of pH up im my solution and that seamed to stabilized the ph.

Got no airstone but two circulation fans in the water reservoir but don’t think circulation is the issue as the PH also increases when I keep it in smaller buckets.