PH Drop - CO2 Injection

[carlyleigh]

Since introducing a CO2 injection kit in just over 2.5 weeks PH has dropped from 7.0 to 6.5... should I bring it back up to 7.0?

Kinda worried this may upset the fish anyone got some advice on this subject.......

 

[jmhart]

CO2 naturally drops your pH. In an aquarium with a KH of 4, a 1.0pH drop indicates 30ppm of co2---the desired level.

Point is, don't worry about the drop in pH due to co2. Generally we worry about changes in pH because it is due to changes in TDS. pH drop due to co2 has nothing to do with TDS, so it's nothing to worry about.


Additionally, most plants enjoy slightly acidic conditions.

 

[jpappy789]

As jmhart said, nothing to stress about with CO2 as pH is only one factor. And trying to raise it would end up being a constant struggle between you, your tanks buffering capacity, and the CO2...very stressful on fish.

 

[beviking]

CO2 naturally drops your pH. In an aquarium with a KH of 4, a 1.0pH drop indicates 30ppm of co2---the desired level.

Point is, don't worry about the drop in pH due to co2. Generally we worry about changes in pH because it is due to changes in TDS. pH drop due to co2 has nothing to do with TDS, so it's nothing to worry about.

Additionally, most plants enjoy slightly acidic conditions.

I'll second (3rd) that reply. The reference to KH should be noted because if your water is low in KH (carbonates) and you do not replenish them (via water changes) then you could run out of KH. KH keeps the pH stable and without it pH crashes.

 

[carlyleigh]

I have just tested my tank and the results are

GH 30
KH 20
PH 6.5
NO2 0
NO3 40 Spiked a bit normally sits around 20......

 

[jmhart]

I'm assuming:

GH = 30ppm, not degrees
KH= 20 ppm, not degrees

Some people do have very hard water, so I might be making a bad assumption.


Of course you know your nitrates are high, but that's nothing a water change can't help. Once you add co2 and as long as you have high light, your plants will start to take care of all that nitrate for you.


So again, the pH drop is nothing to worry about.

 

[carlyleigh]

GH 30 ppm
KH 20 ppm yes correct sorry.....

I had to remove my carbon filters due to treatment i needed to give one of my poorly rams... (Integrated filtration catridge so left me with basic filtration thus a nitrate spike)

Normally sit around 5 -10 ish as my plants gussle the stuff up.....

 

[beviking]

Uh oh...

1 degree is about 17.6 ppm so if your KH is 20ppm, that's not much more than 1 degree. Most recommendations I've read say 3degrees KH to be safe but I don't know how fast 20ppm would be "used up". Again, regular water changes will replenish KH. It's the times when you get busy and happen to miss a water change that poses a problem.