Low Flow & Co2

[JoeQ]

What is the best way to distribute co2 in a low flow / air powered setup? 🤔.

[Pepere]

I would imagine some sort of co2 bell so bubbles dont just escape to the surface…

 

I can say, the Co Ops Easy Flow kits give amazing flow for air driven filtration.  I have retrofitted them with adapters to Penn Plax type UGF plates, and they also friction fit over medium size Lee’s triple flow box filters.

[JoeQ]

On 5/7/2024 at 3:21 PM, Pepere said:

I would imagine some sort of co2 bell so bubbles dont just escape to the surface…

 

I can say, the Co Ops Easy Flow kits give amazing flow for air driven filtration.  I have retrofitted them with adapters to Penn Plax type UGF plates, and they also friction fit over medium size Lee’s triple flow box filters.

Thanks, I was thinking setting up passive co2 system would be my best option. As for flow im not sure I want to retrofit an easy flow kit which IMO will increase flow due to the tappered nozzle. Currently in my 36g im using (2) of these

Which give a nice subtle directed flow.

[Pepere]

I have been pleased with my non co2 17 gallon fish bowl. 
 

I have it free from visible algae which I am thrilled with.  I have mostly easy plants, crypts, anubias, java fern, bacopa, ludwigia repens, hornwort, water lettuce , s repens…

 

growth is noticeably slower, but in the case of Lrepens, that is not a bad thing…

[JoeQ]

On 5/7/2024 at 5:13 PM, Pepere said:

I have been pleased with my non co2 17 gallon fish bowl. 
 

I have it free from visible algae which I am thrilled with.  I have mostly easy plants, crypts, anubias, java fern, bacopa, ludwigia repens, hornwort, water lettuce , s repens…

 

growth is noticeably slower, but in the case of Lrepens, that is not a bad thing…

I'm not sold on it, then again im pushing so little in my 36g that im not even sure if its making an impact. To give you an idea how little a 5lb tank would have lasted me 2 years this November. With 1/4 tank left im only now pushing a bit more to see if it helps a few problem plants I have, but I'm definitely not a fan of the soda water look....

Edited May 7 by JoeQ

[gardenman]

The key with CO2 is to get it absorbed by the water. Once absorbed it'll move through the water column fairly evenly. It's the getting it absorbed before it hits the surface and goes into the air that's the challenge. Finer bubbles get absorbed more easily but those diffusers also tend to clog more easily. People have used CO2 ladders and raceways and other means to slow the rise of the CO2 to allow more time for absorption. Others shoot the CO2 bubbles at their plants. At the rate you're using CO2 a bell or inverted bottle filled with CO2 is probably ideal. The amount of surface area of contact between the bell and water largely controls the amount of CO2 absorbed. A larger diameter bell, inverted bottle, etc, gives more surface area for absorption.

I've been intrigued by the idea of feeding CO2 directly into the airline that's powering a filter for some time. You have your air pump and the line coming from it. A T fitting with the CO2 coming in on the T with a check valve to prevent the air going into the CO2 canister. Then the air/CO2 mix goes into your filter and bubbles its way back to the surface. Not ideal bubble size, and you'd probably have long term issues with the carbonic acid formed from the CO2 combining with the water damaging the filter, but it could be an option. Balancing everything could be tricky.

On the loony fringe side of things, If you want a lot of CO2 in your tank, you could make a very tight-fitting lid with sealed chambers that allow the air from the filters to escape the lid, but then flood the remaining surface area of the tank with CO2. Not a great idea if you have any air-breathing fish like a betta, but nearly the whole surface area of the tank could be the inverted bell or jar in that manner. 

[JoeQ]

On 5/9/2024 at 7:28 AM, gardenman said:

The key with CO2 is to get it absorbed by the water. Once absorbed it'll move through the water column fairly evenly. It's the getting it absorbed before it hits the surface and goes into the air that's the challenge. Finer bubbles get absorbed more easily but those diffusers also tend to clog more easily. People have used CO2 ladders and raceways and other means to slow the rise of the CO2 to allow more time for absorption. Others shoot the CO2 bubbles at their plants. At the rate you're using CO2 a bell or inverted bottle filled with CO2 is probably ideal. The amount of surface area of contact between the bell and water largely controls the amount of CO2 absorbed. A larger diameter bell, inverted bottle, etc, gives more surface area for absorption.

I've been intrigued by the idea of feeding CO2 directly into the airline that's powering a filter for some time. You have your air pump and the line coming from it. A T fitting with the CO2 coming in on the T with a check valve to prevent the air going into the CO2 canister. Then the air/CO2 mix goes into your filter and bubbles its way back to the surface. Not ideal bubble size, and you'd probably have long term issues with the carbonic acid formed from the CO2 combining with the water damaging the filter, but it could be an option. Balancing everything could be tricky.

On the loony fringe side of things, If you want a lot of CO2 in your tank, you could make a very tight-fitting lid with sealed chambers that allow the air from the filters to escape the lid, but then flood the remaining surface area of the tank with CO2. Not a great idea if you have any air-breathing fish like a betta, but nearly the whole surface area of the tank could be the inverted bell or jar in that manner. 

Lots of good insight here. Gives me an idea for later, thank you!