jcbyrne

In his article in the Tropical Fish Hobbyist that just arrived, Amano says that to monitor CO2, measure the ph just before the light goes on in the morning, and again four to five hours later. If it is higher, the amount of CO2 is insufficient, if it is slightly lower, the amount is adequate. If it is much lower the amount of CO2 is excessive.

So, what do you think? What is "slightly lower", "higher" or "much lower"?

hoppycalif

It is permitted to disagree even with Amano! So, I do.

AndyT.

Well, think of it this way...

Overnight the plants release CO2 and consume O2... CO2 being acidic, this means that the pH should have dropped over the night.

During the day this reverses, with the plants consuming CO2 and producing O2. If you don't supplement CO2 the normal cycle would be for the morning to be the time with the lowest pH, just before lights come on. The pH should rise throught he day as the CO2 in the aquarium is utilized by the plants.

Back to what Amano says - I think he is indicating that an increase in pH would show that CO2 is being depleted in the aquarium faster than it is being replaced. So any increase would indicate that there is not enough CO2 supplementation (if you assume that the early morning CO2 and pH levels are ideal).

The pH scale is logarithmic and if I recall correctly (always a problem) each 0.1 change represents a 10x change in pH. A change from a pH of 8 to 7 is a 100x change.

So I would go for a decrease in pH of about 0.2 to 0.4 as being okay and anything larger indicating too much CO2 is being added. But that is just my take on it.

The much discussed drop checker is an easy way to use pH to monitor CO2 levels.

AndyT.

Hoppy, why do you disagree with Amano? The only thing I see as problematic is the assumption that the early morning CO2/pH level is a baseline...

hoppycalif

A change in pH of 1.0 equals a change in ppm of CO2 of 10X, not 100X.
I disagree with Amano, partly for the thrill of doing so, but mostly because I think we get the best results if we try for 30 ppm of CO2 in the water during the time the lights are on. Generally, that means the pH will be higher in the morning, after the CO2 has been lost due to our slight surface turbulence. Then, as we add CO2 while the lights are on the pH will drop until we hit the equilibrium point where we are adding as much as we are losing through the water surface.

I'm not quite ready to challenge Amano on the quality of my plant growing skills, nor on my aquascaping skills, nor on my algae control, nor............

AndyT.

I guess you can see why I was a liberal arts major...

Thanks for elucidating. Makes perfect sense now.

Wheeler

This is a problem. The thrill? You think you get "better results", but you don't. I've never seen your tanks, but I KNOW that you don't get better, 100% reapeatable, results than Amano in any sense. Few do...

Amano does it with half the CO2, a small fraction of NO3 and PO4, and easily as much light as any EI tank.... again and again 1000 times over. Right now, Amano is untouchable. I think we'll get him figured out one day, but EI ain't it.

turtlehead

Amano only has CO2 for the photoperiod and he turns it off at night. By lowering it or increasig, he means it depends on your fish and your plants. Each tank has a different demand and limit for CO2, I lower it if my fish are gasping and I increase it if I see bba or deficiencies from my plants. How much to lower or increase depends on you and your plant, kind of like the EI method.

hoppycalif

I didn't say I could get better results than Amano, no matter what I try. In fact I will say that it is very unlikely that I will ever approach Amano's results. What I did say is that we neophytes, who don't make a business of this, who are still learning, and who could always do a better maintenance job on our tanks, can get the best results if we try to keep the daytime concentration of CO2 in the range of 20 to 40 ppm, which is as accurate as we are likely to ever know it in any case. My goal is not to find Amano's magic methods, but to find a method that works for me, with my skills, my devotion to the maintenance, and my budget. I think most of us should try various ideas to see which we can make work the best, then use that.

Wheeler

Yes you did...

Hoppycailf said:
"I disagree with Amano, partly for the thrill of doing so, but mostly because I think we get the best results if we try for 30 ppm of CO2 in the water during the time the lights are on."

My mistake. You said you get the BEST results...

No matter what works for you, you should consider the intitial question. How can you say what's best, and then turn around and say the guy you're contradicting is far superior to you in skill. I swear I'm not trying to be combative, but you're trying to help someone wrap their head around Amano vs EI (Basically). Sounds a little biased to me... again, in the interest of discussion.