CO2 and PH questions

[Edward61]

My PH reading prior to adding CO2 was 7.5 I used a purchased test kit and tested the KH and GH this morning using water from the aquarium: KH was 4 drops (71.6 ppm) and GH was 7 drops (125.3 ppm). A calculation spreadsheet I found online computes to lowering PH to 6.9 to get a 19.064 ppm CO2 reading.

I use a PH controller with the CO2 setup so keeping the PH at a lower level should be automatic. I am still having some issues with adjusting the flow rate, but it has only been a couple days so far and from what I read tweaking is required for a few days.

1. If I lower the PH from 7.5 to 6.9 are my fish going to become stressed or die?
2. Will weekly water changes impact the PH level since I used CO2 to drop it so far?
3. Should I add peat moss to my filter (Fluval 305 with 3 trays) to help drop the PH?
4. Is there anything else I am missing or need to know?

 

[mfdrookie516]

No worries about the pH.... the kH is what matters, and co2 doesn't affect it, the way I understand it. FWIW, the pH in my 125 is 6.4 due to the peat and all from the dirt. My tap pH is 7.8. I do 50% pwc's weekly, no ill effects as of yet.

 

[ChizerBunoi]

I wouldn't worry about it, especially since you have a controller. Just slowly dial your co2 and monitor, meaning drop the ph on the controller half a notch and give it a day to see what the level is at.

When you do the water changes, don't worry about the PH swing.You can even put your PH controller on the lights timer and have it turn off when the lights are off. That will save on co2.

I would highly recommend buying a $8 co2 drop checker/indicator using the 4dkh solution that you made. Just use that as a monitor instead of all the test kits. Just know that it takes 2 - 4 hrs for the indicator to show the proper co2 volume.

Don't worry about adding any peat. Just fertilize and you'll see the plants grow.