Using Co2 To Lower Ph?

plan on keeping discus soonish but my tap comes out 7.8-8.0. Want to lower pH and do it consistently (have heard chemicals may not be best bet) normally would use tannins but want clear water. . . My understanding is CO2 can be used to lower pH. . . Thoughts?

If so I was planning on adding a diffuser to the sump.

Also adding CO2 at high water temps ok as long as I’m airating the water?

 

CO2 in large enough quantities to lower the pH will kill all your fish.

Why not let nature take it's course - bio activity tends to lower the pH in a tank all by itself.

 

So the ph changes from co2 are much different than a low ph. Ph will actually fluctuate a bit in a planted tank of any ph with or without co2 injection because of the natural reapirations of the plants.

The amount of co2 required to reduce ph in a tank varies greatly based upon the actual water parameters and depending on what's keeping your ph levels up around 8 it may well take toxic levels of co2 to bring down to whatever your desired level is.

The low ph that you'd be trying to achieve for discus would be caused not by heightened co2 levels but rather from reduced mineral content in the water. Very different mechanisms that happen to share a similar effect.

Note : I've recently been doing some reading and research on discus that are kept in much higher than the common consensus ph values and are thriving and even in some cases breeding or attempting to breed. If you don't want to tinker with water parameters and maintaining them it might be worth looking into discus that are being raised and bred in higher ph waters that more closely align with your source water.

 

Yeah I have read that in Germany people have had luck breeding Discus in high pHs so I may start looking into that. I’ve also read that it’s very possible to keep discus in high ph (mainly captive bred ones ) but really I’m more interested in the breeding than I am just keeping

 

Domestic discus will usually breed in tap water. RO water is frequently used to get wild discus to breed.
If you age your tap water to let the dissolved gasses from tap to escape, you may have a lower PH.

 

What happens if you just let the tank run for a week or two without any pH adjusments? Where does it shake out?

My tap water comes in at around 7.5 but a week in the tank with no pH correction and it's a 6.5 or lower.... It drops like a stone in a hurry. I run crushed coral, a little limestone, and pH buffer to keep mine at 7....

The natural biological cycle tends to run things toward acid.