CO2 on/off times

scottward

Guru Class Expert
Oct 26, 2007
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Brisbane, Australia
Hi Tom.

My lights come on at 2pm, and go off at midnight, so 10 hours.

My CO2 follows the same pattern.

I did have it coming on 1 hour before the lights, but I stopped doing this thinking I was probably just wasting gas.

Is there any 'best' way of deciding when to turn the gas on/off?

Scott.
 

VaughnH

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When you use an external reactor it tends to build up a bubble of CO2 at the top during the time the CO2 is on. When you shut off the CO2, that bubble continues to add CO2 to the water for many minutes. That would be a reason for shutting off the CO2 at least a half hour before the lights go off. For other methods of adding CO2 I don't see a good reason to shut it off more than a few minutes early.

If the method you use is effective at getting CO2 into the water, it shouldn't take more than a half hour to build up a substantial concentration in the water, so that seems to be the longest you would want it on early. I doubt that it is very critical though.
 

jonny_ftm

Guru Class Expert
Mar 5, 2009
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Hi VaughnH,

How could you explain please that I have to turn on CO2 5h before lights so that my drop checker gets a lime green when lights are on. During night, it turns dark green and it takes a while to get the good lighter green colour.

Also, if I increase the bubble count to shorten this 5h startup period, at the end of teh day I turn with a yellow drop checker

Any idea why I have such a phenomenon. This happens since I increased my surface movement, 24/24, but it is really a small movement, no water surface break despite clearly visible from top sight

edit: I reduced since yesterday my light from 4x54W to a 2x54W (+3h burst 4x54W that I could stop, just not to cut half life suddenly on plants and give me a room to adjust slowly new CO2 needs)

Many thanks for your help
 

scottward

Guru Class Expert
Oct 26, 2007
958
10
18
Brisbane, Australia
jonny_ftm,

The only thing I can think of relates to VaughnH's comment to me about using an effective method of getting the CO2 into the water.

Perhaps the method you are using to get the CO2 into the water is very inefficient?

Just a thought - I am by no means an expert at this -- yet!

Scott.
 

scottward

Guru Class Expert
Oct 26, 2007
958
10
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Brisbane, Australia
VaughnH, thanks for your help, by the way.

My drop checker is always yellow.

I think drop checkers, from everything I've read, are a complete and utter waste of space.
 

jonny_ftm

Guru Class Expert
Mar 5, 2009
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I use the AM 1000 and it never fills with air/CO2

I tried the drop checker at many locations, no change

Really since I begun focusing on CO2, I only have problems (actually the plants are rather fine exept A. Reineckii, but I never feel satisfied with CO2). Maybe after all the best would be a non CO2 thing or really low light so even the few CO2 we provide would be more than enough for our plants
 

scottward

Guru Class Expert
Oct 26, 2007
958
10
18
Brisbane, Australia
jonny_ftm;37142 said:
I use the AM 1000 and it never fills with air/CO2

I tried the drop checker at many locations, no change

Really since I begun focusing on CO2, I only have problems (actually the plants are rather fine exept A. Reineckii, but I never feel satisfied with CO2). Maybe after all the best would be a non CO2 thing or really low light so even the few CO2 we provide would be more than enough for our plants

I know what you mean. My tanks looked better before I touched CO2. But it's hard to give up.
 

jonny_ftm

Guru Class Expert
Mar 5, 2009
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Thanks for trying to help and sorry for having hijacked your topic :eek:

I'm starting a new thread in subscribers area to discuss specifically, maybe once for all, all my concerns on this CO2/Light enhancements
 

scottward

Guru Class Expert
Oct 26, 2007
958
10
18
Brisbane, Australia
No probs.

I think the real problem with this hobby is the badly distributed knowledge. You can pick up any aquarium book anywhere about plants and chances are it is full of things that have been proven wrong, scientifically, by guys like Tom and his team.

I have read so many of these books in the past that I am conditioned to think things should work a certain way...I have to relearn now!

Even Dianna Walstads book, which I thought was the best thing going, has some things in it that are definitely wrong.

Tom - when you finally get the time to write a book you will be a rich man (and deservedly so, of course! ;-)

jonny_ftm - we've just gotta re-learn. Forget about crap that you find in books, there is plenty of proof that the guru team on here are correct...stick to this website and you should be right.
 

VaughnH

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A drop checker can't keep up with the rising CO2 concentration, given its 2 hour or so response time. And, the rate of response is very likely proportional to the difference between the concentration in the tank water and the drop checker water, so the drop checker response is probably assymtopic, never quite catching up with what is in the water. I think the value of a drop checker is solely its ability to show you that you don't have nearly as much CO2 in the water a few hours after you start injecting it, as you would believe from pH and KH readings. This acts as a cheering squad to help you find the nerve to keep increasing the bubble rate until you get that green-yellow color. After that it is a trial and error process to get the concentration as high as you can without harming the fish.
 

Gerryd

Plant Guru Team
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Sep 23, 2007
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VaughnH;37172 said:
This acts as a cheering squad to help you find the nerve to keep increasing the bubble rate until you get that green-yellow color. After that it is a trial and error process to get the concentration as high as you can without harming the fish.


Well said!
 

jonny_ftm

Guru Class Expert
Mar 5, 2009
821
2
16
VaughnH, I see it better now, many thanks,

Really was thinking this drop checker is a good way to go. Maybe I should increase bubble count rather than increasing the delay between CO2 start and lights on. I'm just so scared to kill my fish. I'd be very sad, my 3 years old sun also. All the fish have a name/ID. Killing them with CO2 error would be sad. Also, the trouble to find a trustful shop to get replacement healthy fish...

Anyway, I'll give it some days with the actual status. Maybe light intensity decrease alone would make the actual situation ok for the plants. The drop checker now keeps a lime-green consistent from the time lights are on, upto 2-3h when they're off

Thank you again for supporting. Focusing on CO2 is harder than I thought. maybe I'll use a mist way finally to make it easier to spread in the tank
 

scottward

Guru Class Expert
Oct 26, 2007
958
10
18
Brisbane, Australia
jonny_ftm;37182 said:
VaughnH, I see it better now, many thanks,

Really was thinking this drop checker is a good way to go. Maybe I should increase bubble count rather than increasing the delay between CO2 start and lights on. I'm just so scared to kill my fish. I'd be very sad, my 3 years old sun also. All the fish have a name/ID. Killing them with CO2 error would be sad. Also, the trouble to find a trustful shop to get replacement healthy fish...

Anyway, I'll give it some days with the actual status. Maybe light intensity decrease alone would make the actual situation ok for the plants. The drop checker now keeps a lime-green consistent from the time lights are on, upto 2-3h when they're off

Thank you again for supporting. Focusing on CO2 is harder than I thought. maybe I'll use a mist way finally to make it easier to spread in the tank

Tom and the crew always suggest making slow and gradual changes to CO2. If you follow this advice, your fish should be fine.