# DIY Co2 and Air pump Question



## SongCloud (Aug 30, 2005)

I've been lurking around here for some time now and I finally find the need to ask a question!! Every other time I've had an issue, I've found a thread where it was already discussed, but this time I have a new idea. 

I am planning on starting Co2 on both my 10 Gal and 5Gal tanks using a DIY method for now. (too poor for any pressurized setups yet!  ) I use Flourish Excel, but I have heard of some plants not responding too well to it (ie. melting under high doses) I have a Co2 Tester from Azoo, which shows that the Excel is working, but I have yet to see any pearling or even the growth that I am looking for and I hope that Co2 will provide this for me. 

I'm planning on using a glass diffuser for the Co2, but I have an air pump set up on a timer that is opposite my light timer (light goes on, air is off, lights out, air kicks on, since I have been seeing some minor PH swings from night to day) If I keep that cycle going, and start DIY Co2, will the increased O2 from the air pump offset the Co2 diffusion at night enough so as not to cause an overall Co2 increase at night??


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## Laith (Sep 4, 2004)

Hello and welcome to your first post(s) on APC!

I would be surprised that any CO2 test can detect the presence of Excel. Excel is not CO2 but contains a carbon compound that provides an alternative source of carbon for the plants. It has no impact on pH as far as I know. It does help bring carbon to the plants, especially in smaller tanks. I've seen opinions that say that Excel is about 1/3 the efficiency of CO2.

O2 and CO2 are not mutually exclusive; adding more O2 does not reduce the amount of CO2 available and vice versa. However, an airpump will agitate the surface of the water enough so that more CO2 is lost into the air than without an airpump.

Many people with pressurized CO2 turn off the CO2 when the lights go off as the plants stop using it. In your case with DIY, you cannot easily turn it off so adding an airpump will give you extra insurance against too high of CO2 levels when the lights are off.

I've heard that Amano runs airpumps at night in addition to turning off the CO2 so you'll be in good company!  

Personally I hate airpumps and never use them and never found a need for them...


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