# PH 7.6 to 6.4 ?



## John44 (18 Nov 2016)

Hi

I tested my water today about 2 hours before the CO2 started and got a reading of 7.6 - 3 hours into the CO2 \ Light cycle I tested again and got 6.4

I appreciate its quite a general question but does that seem right ?

Regards
John B


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## tadabis (18 Nov 2016)

I am not a pro, but it looks like you are getting to much co2 in your tank. What colour is your drop checker? In my tank I have 6.9 ph when co2 is off and 6.4 - 6.5 ph when co2 running and I have about 35 ppm co2 @4kh. Test your kh and ph when co2 is running and youll see if it is OK or not...


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## Chrispowell (18 Nov 2016)

Yep perfectly normal, sounds like you are wasting some gas though, you are really looking for a single point drop by lights on (6.6).

Then aiming to hold that level until lights out


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## dw1305 (19 Nov 2016)

Hi all,





John44 said:


> tested my water today about 2 hours before the CO2 started and got a reading of 7.6 - 3 hours into the CO2 \ Light cycle I tested again and got 6.4


You can't really tell from the tank water, as you don't know the exact carbonate hardness (dKH).  

The problem is that pH isn't a very useful measurement without some measure of water hardness.

Do you have a drop checker?

cheers Darrel


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## John44 (19 Nov 2016)

Hi

Drop Checker should be here today, I can test PH and GH and so kit for KH will also be here today. I will test prior to Co2 and lights and again once Co2 and lights have been on. Will post the results

John B


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## kadoxu (19 Nov 2016)

Someone should make this chart a sticky:





You want to be somewhere in the grey area when CO2 is on.


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## John44 (19 Nov 2016)

Well my JBL CO2  Drop Checker has arrived and its installed - so now I wait and see what colour it changes to - the CO2 has been on for 3 hours and I have a pH of 6.6 - I can see some pearling on the plants so I think thats good

John B


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