Do I need CO2 if...

[sepehr]

Hi, I was wondering if I needed CO2 for my 100 gallon tank (with good lighting) given the fact that the PH is at 6.7 and the KH at 3.0 which equals to 18 Carbon miligrams per liter and a good range according to experts is between 10 and 20 mg/l. Besides, if my PH is steady at 6.7 (due to the water, driftwoods, and the Red Sea Flora Base), wouldnt injecting pressurized CO2 bring my PH way down? I know some CO2 systems have a PH check on them which shuts off the CO2 if it hits the specific PH value but I want my PH to be where it is currently (6.7) because is suitable for the kind of fish & plants that I have and for this reason I thought even if I got a CO2 system (with PH controler), it would be off almost all the time since I would set it on 6.7 and thus hardly injecting any CO2 supply to the tank...I could very well be wrong on this, I need your advice.

TIA

 

[jasonG75]

What is your Stock? Plants and fish

 

[KarlTh]

Your guess as to your CO2 levels assumes there are no other acids or buffers in your water. It's unlikely to be correct. I would imagine you have far less CO2 than you think and would benefit from raising the KH and injecting CO2.

 

[sepehr]

What is your Stock? Plants and fish

The tank went through a 5 week cycle with 5 female guppies then I added anubias nana, valisneria nana, cryptocorine lucens, ludwigia repenes but later on Im planning on adding more demanding species like golossostigma elatinoides and as far as fish goes I have 11 Rummy-nosed & 7 cardinal tetras for now. My question regarding CO2 was about my near future plans than my current setup.

Thanks

 

[sepehr]

Your guess as to your CO2 levels assumes there are no other acids or buffers in your water. It's unlikely to be correct. I would imagine you have far less CO2 than you think and would benefit from raising the KH and injecting CO2.

See, this is what confuses me the most. The PH, KH, temp., and CO2 are all inter-related. Balancing a planted tank with fish is kind of complicated for newbies like me. Could you PLEASE link me to a site or to an article which really explains all these in depth.

Thanks

 

[plantbrain]

See, this is what confuses me the most. The PH, KH, temp., and CO2 are all inter-related. Balancing a planted tank with fish is kind of complicated for newbies like me. Could you PLEASE link me to a site or to an article which really explains all these in depth.

Thanks

Balancing the tank is best approached with each type of dosing and then decide which method will allow you to get to the goal you want.

So........

http://www.tropica.com/advising/technical-articles/biology-of-aquatic-plants/co2-and-light.aspx

CO2 will help the plants use the light much more effectively, so you waste less energy, cost, risk of algae.

CO2 has a huge fear factor and most all have tried to worm their way around not using it, thinking in only light and nutrient terms.
Submersed conditions are VERY different for plants than terrestrial, this has a lot to do with out mental issues with the CO2 avoidance.

Read the article carefully.
This will help a great deal.

Regards,
Tom barr

 

[sepehr]

Balancing the tank is best approached with each type of dosing and then decide which method will allow you to get to the goal you want.

So........

http://www.tropica.com/advising/technical-articles/biology-of-aquatic-plants/co2-and-light.aspx

CO2 will help the plants use the light much more effectively, so you waste less energy, cost, risk of algae.

CO2 has a huge fear factor and most all have tried to worm their way around not using it, thinking in only light and nutrient terms.
Submersed conditions are VERY different for plants than terrestrial, this has a lot to do with out mental issues with the CO2 avoidance.

Read the article carefully.
This will help a great deal.

Regards,
Tom barr

Thanks Tom, it all made sense, it's a very helpful article.

Cheers,
Sepehr

 

[jpappy789]

It is nearly impossible for an aquarium with ample surface agitation to hold 18 ppm of CO2 regardless of pH and KH levels. At most you will actually have 2-3 ppm as that is what equilibrium levels are with the air surrounding the tank. That is why people who inject CO2 choose not to have HOBs or other means of filtration that cause unnecessary splashing of the water surface. All that extra CO2 is just being off gassed.

 

[sepehr]

It is nearly impossible for an aquarium with ample surface agitation to hold 18 ppm of CO2 regardless of pH and KH levels. At most you will actually have 2-3 ppm as that is what equilibrium levels are with the air surrounding the tank. That is why people who inject CO2 choose not to have HOBs or other means of filtration that cause unnecessary splashing of the water surface. All that extra CO2 is just being off gassed.

I have attached the spray bar about 5 inches beneath the water surface and when I get my CO2 Im planning on placing way down at the bottom at the opposite side of the spray bar. But then again wouldn't a strong current from the filter help to defuse the bubbles before they reach the surface? Coz in that case wouldnt placing the defuser underneath the spray bar be more logical?

 

[tanker]

The defuse the CO2===The longer the CO2 bubbles are in contact with the water the better. Having the CO2 bubbles come from under the sray bar would only add a few more seconds of contact===IMO that would help, but not to a great deal.