Co2 Question

[Juggler75]

Hi, got asked this question today and as I didn't have a clue thought I'd throw it out there for you experts. Would appreciate some detailed responses and suggestions so I can relay them back (or he can view them). Thanks in advance.

Question asked was:
Currently using a yeast diy c02 maker in a 2litre bottle, i have a 6.5ft tank running off a 3ft sump now the question is can i put the air line from the c02 into the sump return pump so it gets defused by the impeller of the pump, will the c02 be ok still as it is going just over 3.5mtrs in the return pipe then through a spraybar back into the tank ? Am thinking of using 2 CO2 reactors in the near future.

Now as I've never seriously considered anything but low tech I'm not in a position to help but maybe one of you could? I'll send him a link to this thread and hopefully he'll join and give further details as required.

 

[DrRob]

Risk with a DIY yeast system is always the lack of pressure. If you have enough resistance they stop flowing. If you put it in the right place so it flows then the impeller should break up the bubbles and they'll largely be diffused in the return flow and you'll be fine. Positioning will be the challenge.

With a check valve, at least you shouldn't get water going back down the pipe.

You can DIY a CO2 reactor as well, but you'll still get the same pressure problem.

To be honest, for the size of tanks involved he may find it not worth bothering, as he's going to need a lot of CO2 reactors, and with a sump and a big tank, even the bigger pressurised cylinders won't last that long.

 

[Juggler75]

Thanks for the quick answer.

Is there any way to increase the CO2 levels in the tank setup as described that wouldn't be throwing cash down the drain to achieve?

 

[Mikaila31]

Pressurized is the only way on a tank that size. As far as the larger cylinders go I don't see why they wouldn't last. My 5# tank lasts 3-4 months on a 55 gallon, thats the 2nd smallest cylinder size I can get. It would be better IMO to just lower lighting, you don't need CO2 addition to have a nice planted tank. I'm not sure how the sump is setup but any surface agitation really drives CO2 out of the water. If the sump causes a lot of this then yes CO2 won't last long as you will have to over-inject to compensate for all the CO2 being driven out.

 

[Lethal Monkey]

On a tank of that size they would be best using a pressurised co2 system due to te sump size however using the 3.5m return pipe would be a nice way of dissolving the co2