ph Drop

[simon Coram]

In the morning its 7.2, evening after co2 has been on its 6.8.


The KH is 6 both times This gives me 28ppm co2 later in the evening and 11ppm co2 in the morning.

Does this sound about right. Is the ph fluctuation normal.

 

[ian_m]

How are you measuring pH ?

pH pen I assume ?

It should be pH pen, not test kit, so take a cup of water out the tank and test pH in case you have electrical interference issues with your pH pen.

See if the cup of water outgasses overnight and test in the morning ?

 

[simon Coram]

I use a test kit.

 

[ian_m]

I use a test kit.

That is you answer. Something else in your water is interfering with the test kit. Could be left over dechlorinator, high nitrate, chloride or some other source.

The CO2 pH changes are really only approximate when using a pH pen as opposed to a test kit.

What does your drop checker say ?, as this is completely independent of tank water contents.