Question: Ph too high

[kristie85]

Hi, can changing the carbon in our fluval lead to ph increase? 2 weeks ago ph was 6.8 as to be expected in a cycled tank (5 months running) and last monday was our regular water change day (20%) And carbon was due to be changed. Will this change ph levels? We have also installed a light to help plants grow which has not affected the axies as it only runs for 6 hours during the day. This is the only other change we have made. We did another 20% water chsnge this evenibg and added half a teaspoon of kh powder to try and regulate ph.
Thanks

 

[Jennewt]

What do you mean by "too high"? Even 8 or 8.2 is generally OK. Plants affect the pH, making it more basic during daylight hours. Try testing at different times of the day.