Diy Co2 System

[Robbo89]

So I'm looking at giving one a shot while I've got a few weeks off from school.
 
I don't really have any plants which require c02:
 
Anubias barteri (in a few days)
Hygrophilia
Corkscrew Val
Crypt Wendtii
 
but am looking at maybe adding some Rotala Wallichii which I hear does require c02 and high lighting (I only have 1wpg).
 
My questions are, if I was to give this homemade system a shot
 
1. How likely is it that I could harm my fish, I currently only have 3 platys in there but am adding 8 Black Widow Tetra and 2 Peppermint BN over the next 5 days. 
2. I hear I need to run an air stone while the lights are out to prevent the fish from 'choking', is this true? ( I don't own one)
3. I know plants melt when adjusting to new conditions, so if I for whatever reason stopped dosing c02 after a few weeks will my plants melt initially and then melt again when if I had to stop? So pretty much I'm asking: If I start does it have to be permanent? 
 
Thank you heaps for your time reading this, I love experimenting but don't love killing fish!

Also, what do you guys think about the Rotala.. is it foolish to buy it for this tank? (with only 1wpg)

 

[KirkyArcher]

The safest way to use a DIY Co2 generator is to include the use of a bubble counter/scrubber water bottle to prevent the contents of the yeast/sugar/bicarbonate of soda (alcohol) within the generator bottle/s from finding it's way into the tank. I don't know how big your tank is but usually 2lt of mixture will suffice. Rotala Wallichii will be a costly challenge to begin with retailing about £6 a plant in the UK, no need to have air stone if you have good water flow surface agitation from your filter. Co2 dosing doesn't have to be permanent but after you see the spurt of strong healthy plants you'll be inclined to continue, I have just under 1.5 wpg and my "reds" are doing great and I too intend to give the Rotala Wallichii a go in the not too distant future, My Co2 is running 24/7 and all flora and fauna are in good health.

 

[Robbo89]

Awesome ! Thanks man, do you run off a professional co2 system? Or a homemade one? In that case I'll go ahead and get myself ready to set the c02 up. My tank is  around 90 L, how would I set up a bubble counter? I'm ordering the Rotala off this site, so honestly the price isn't that bad, but the cost for shipping on that site is so I really want to get myself set up to make this work. The thing about the surface agitation is that my tank is in my bedroom... So I have some but really quite minimal oxygen input through the surface of the tank, with this in mind would you suggest I look into an airstone? And what should I be expecting once I start dosing, melting my plants initially?  Thank again, Robbo.

 

[thomtom]

I have had DIY Co2 running for about a month now and as KirkyArcher said once you start you will not want to go back. I have a 100L tank and I run my Co2 24/7 without an air stone and have had no problems so far.
You will want surface agitation in some way though, doesn't need to be extreme, just a ripple across the entire tank will be fine.
 
It will take a few weeks/months to get your mixture right (bubble rate vs how long a bottle lasts).
 
Good Luck!

 

[DrRob]

No, don't run an airstone, they're counterproductive in CO2 tanks, some surface ripple will be fine.
 
A bubble counter is as simple as a plastic drinks bottle half full of water with 2 tubes going in, 1 is long and the bottom is underwater, the second is short with it's end in the air gap. The CO2 goes into the long tube and bubbles through the water, giving you a way of spotting the rate of flow and also trapping any debris that makes it out of your generator before it hits the tank.

 

[Robbo89]

After researching further the past few hours I realised what a bubble counter was and felt pretty stupid for not thinking of it earlier As for the diffuser, what would you guys suggest? I know the conventional half bottle with a sponge in it method however that would look really messy in my tank Also, does it matter whereabouts in the tank the diffuser goes? As in near the plants that need it, in the centre at the very bottom and such?

On the airstone, I realise they are counterproductive to the c02 but the c02 does nothing at night correct? as the plants need the light to photosynthesis meaning at night they cellularly respirate. Wouldn't this further reduce oxygen levels by double at night, from the fish and the plants taking it out? A combination of reduced oxygen and extra c02 would be a problem.. I thought haha Thanks anyway guys really appreciated!

 

[KirkyArcher]

I used to use a JBL ProFlora Taifun diffuser, but this was a little conspicuous in the tank and so now I just use a marina round air stone  about 25mm diameter, but a word of warning using an air stone requires more internal pressure than bubble ladder type diffusers, so you need to ensure that all hoses are good and gas tight sealed, and that the bottles used as reactors & bubble counters can take the additional strain, I've heard stories of exploding generator bottles so I decided to use some old Soda-Stream bottles which are very robust just incase, you are very correct about Co2 at night, but you can have two dissolved gasses or more at the same time, the plants will use the Co2 and the fish will use the "air" disconnecting at night and reconnecting during daylight most probably will take about 2-4 hours to build up enough gas pressure to start producing bubbles in the tank.

 

[Robbo89]

Yeah, my intention was to run an airstone at night in addition to the c02, as you said, disconnecting the c02 at any time would be pretty inefficient. So with that in mind, would you suggest I a) Run an airstone 24/7 AND the c02 24/7  or b) Run an airstone on a timer to start when the lights go off (eg. 8pm - 10am) AND run the c02 24/7 ? Cheers.

 

[This Old Spouse]

I had mine hooked up to my powerhead which was just aimed straight across the tank. Seemed to do nicely.

 

[Robbo89]

So I actually completely set up the system a few hours ago, so far no bubbles but thats completely normal. 
For my 3 Litre generator I used a mixture of:
 
2/3 Luke Warm Water 
3 Cups Sugar
1.5 Teaspoons Baking Soda
3/4 Teaspoon of Yeast (activated in warm water)
 
 
This seemed to be the best performance wise I could find off the internet, so we'll see how it goes. As for diffusion my tubing runs down my tank and then stops in the centre of my canister filter's intake pipe, running the c02 through the entire filter and dispersing the tiny bubbles through the spray bar and into the tank. I'm running no additional airstone, and hoping that the rippled (not splashed) surface created from my spray bar will introduce sufficient oxygen. I suppose only time will tell ... fly or die with this one boys (and girls) ! haha