co2 and kh question
- Thread starter timwag2001
- Start date
It shouldnt affect it but i am not an expert. I have never heard of co2 injection effecting water params.
Injecting CO2 into the tank will cause the PH to drop. If it drops far enough, it will turn the water acidic. If you have anything in the tank that is made of KH, then it can dissolve it if it turns the water acidic enough and release the KH into the water. If you use a PH monitor that controls the CO2 regulator, this will cause greater amounts of CO2 to be put into the water as the KH goes up, because KH raises the ph of the water. In essence, it turns into a death spiral for the O2 breathing organisms in the tank.
wow. never looked at it like that. you just answered a ton of questions for me. thanks. i was blaming a bunch of deaths in my tank to stirring up my substrate. but i just recently turned my ph monitor down gradually to 6.7. i had crushed coral in my filter. i lost about 10 fish.
****...
so what about my kh level in my water ( i removed the crushed coral ) will the co2 disolve that from my water or is the only way to remove that with a water change.
****...
so what about my kh level in my water ( i removed the crushed coral ) will the co2 disolve that from my water or is the only way to remove that with a water change.
The quick and simple answer regarding removing KH from the tank is to do a water change. Some plants can actually use dissolved KH if there is not enough CO2 in the water, and I had this happen to me before I started injecting CO2. I think it was my swords that were consuming it.
Another thing you need to watch is the KH value of your water supply, especially if you are on city water. I'm on city water and the water has a higher KH value out of the tap during the winter. That threw me off the first time it happened.
You should really think about investing in a cheap KH test kit. I think they run about $5. I test the KH every time I do a water change, and sometimes in between water changes in the middle of the week. I keep my KH at 10 and my ph around 7.1 to 7.2. That seems to work out well for me since I have snails and plants in all of my tanks. It keeps the snails' shell from eroding and it keeps my plants and neocardinia shrimp pretty happy.
Another thing you need to watch is the KH value of your water supply, especially if you are on city water. I'm on city water and the water has a higher KH value out of the tap during the winter. That threw me off the first time it happened.
You should really think about investing in a cheap KH test kit. I think they run about $5. I test the KH every time I do a water change, and sometimes in between water changes in the middle of the week. I keep my KH at 10 and my ph around 7.1 to 7.2. That seems to work out well for me since I have snails and plants in all of my tanks. It keeps the snails' shell from eroding and it keeps my plants and neocardinia shrimp pretty happy.
the reason that i had crushed coral was because my water comes out of my well with less than 1 dkh. monday night my kh was 4dkh tonight it was 9dkh
9dKH and 6.7ph is pretty much fatal if you are injecting CO2.
Refer to this chart:
http://www.fishchannel.com/freshwater-aquariums/planted-tank/co2-basics.aspx
Instead of using crushed coral with an acidic ph, you might want to think about using baking soda (sodium bicarbonate) to raise the KH after a water change. That is what I do. I have it down to a science now. After the water change I do a KH test. Add in the required amount of baking soda, and then do another KH test 30 minutes later. Here is a calculator to help you with the amount of baking soda to use:
http://dataguru.org/misc/aquarium/CalKH.asp?Gallons=75&KH=1&measure=0&Baking+Soda+%28Teaspoons%29=0.08&SKH=1&EKH=2&pHChange=0.69
The lower the ph the less baking soda you need because the KH doesn't need to be as high. However, the lower the ph the less room for error with the baking soda.
http://dataguru.org/misc/aquarium/CalKH.asp?Gallons=75&KH=1&measure=0&Baking+Soda+%28Teaspoons%29=0.08&SKH=1&EKH=2&pHChange=0.69
The lower the ph the less baking soda you need because the KH doesn't need to be as high. However, the lower the ph the less room for error with the baking soda.
isnt this table only true if you dont have any buffers present? would crushed coral be considered to be a buffer?
The table isn't correct if certain buffers are used, the predominant ones I can think of are PH buffers. I don't know the specific answer regarding crushed coral since I don't use it. Maybe somebody else on here would know and/or maybe it is mentioned in the article to that chart.