Aquatic Plant Central - View Single Post

BryceM · 03-10-2006, 12:28 PM

Hoppy, look at the hornets nest you stirred up.

I think dkfennel has a good point. One person's CO2 reading is not necissarily the same as another person's. I've been running ideas by a friend of mine who graduated as a chemistry major from Dartmouth. He is, without a doubt, one of the 10 smartest people I know. His conclusion is that the relationship between CO2, pH, and acid buffers in aquarium systems are too complicated to model with simple methods. There are just too many variables.

I think that a couple of ideas have merit. One is to add CO2 unitl the fish show distress and back off a bit. This method has drawbacks. I'm pretty convinced you can slowly acclimate fish to conditions that they wouldn't normally do well at. Therefore, the speed at which you drop the pH is important. The other problem is that it's not always easy to get consistently accurate pH readings, even with an electronic meter.

The other idea is to degas a water sample and plan on dropping the pH about 1.0 units. I'm not sure that I know 'exactly' what ppm of CO2 this gives me, but it seems to work and is probably a good place for a newbie to start. I do think it removes certain innacuracies inherent to the traditional KH/CO2/pH chart.

People's estimation of their CO2 is probably about as accurate as their estimation of light reaching their plants. It doesn't take much checking with light meter to figure out that watts/gallon is an absurd unit of light. It's just the most convenient one we have.

03-10-2006, 12:28 PM	#37 (permalink)
BryceM Administrator Join Date: Nov 2005 Location: South Central Idaho, USA Posts: 4,262 iTrader Ratings: 42 iTrader Positive Rating: 100% Plant Points: 178534	Hoppy, look at the hornets nest you stirred up. I think dkfennel has a good point. One person's CO2 reading is not necissarily the same as another person's. I've been running ideas by a friend of mine who graduated as a chemistry major from Dartmouth. He is, without a doubt, one of the 10 smartest people I know. His conclusion is that the relationship between CO2, pH, and acid buffers in aquarium systems are too complicated to model with simple methods. There are just too many variables. I think that a couple of ideas have merit. One is to add CO2 unitl the fish show distress and back off a bit. This method has drawbacks. I'm pretty convinced you can slowly acclimate fish to conditions that they wouldn't normally do well at. Therefore, the speed at which you drop the pH is important. The other problem is that it's not always easy to get consistently accurate pH readings, even with an electronic meter. The other idea is to degas a water sample and plan on dropping the pH about 1.0 units. I'm not sure that I know 'exactly' what ppm of CO2 this gives me, but it seems to work and is probably a good place for a newbie to start. I do think it removes certain innacuracies inherent to the traditional KH/CO2/pH chart. People's estimation of their CO2 is probably about as accurate as their estimation of light reaching their plants. It doesn't take much checking with light meter to figure out that watts/gallon is an absurd unit of light. It's just the most convenient one we have.