New to aging water, odd results

[compchick813]

Hi, so I plan on setting up my 125 with discus in a few months, and I aged some water (with aeration) to test how the pH changed since I hadn't done that before. Out of the tap, our water is pH 7.5/7.6, GH 10, KH 8. These were the results:
1 hour: 7.4
2 hours: 7.2
3 hours: 7.0
4 hours: 7.0/6.8
5 hours: 7.0/6.8
6 hours: 7.0/6.8
15 hours: 7.5
24 hours: 7.5
30 hours: 7.5
39 hours: 7.5

It seems odd to me that the pH dropped and went back up. What would cause that? Or is what should happen? I thought it would be more likely to go up and stay there. Any insight would be appreciated, thanks!

[DerekFF]

Doesnt matter really. It never swung much in either direction and with kh/gh numbers like that its about very stable and probably also the reason for the varies ph readings. Dont sweat it it looks fine to me. Its probably hard water in terms of tds though should you ever plan on breeding just an fyi. But for raising and keeping discus its perfecto!!!

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[compchick813]

Thanks!

[DiscusDrew]

Doesnt matter really. It never swung much in either direction and with kh/gh numbers like that its about very stable and probably also the reason for the varies ph readings. Dont sweat it it looks fine to me. Its probably hard water in terms of tds though should you ever plan on breeding just an fyi. But for raising and keeping discus its perfecto!!!

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+1, the only thing I see clearly is that your water needs to age at least 15 hours before it stabilizes, I agree that your water probably has very high TDS given your Kh, which is whats responsible for keeping your Ph relatively stable. I hope you all the best, your water sounds great for raising discus.