Do I Need To Add Co2 To My Aquarium

[Sanctuary80808]

Hello everyone,
I am going to be starting a new aquarium which is 200litres and will have 2 x 30w marine white t8 lighting. Is it worth adding a pressurised CO2 system (using a fire extinguisher) to my aquarium? I will be adding ferts when needed (tropica plant nutrition+) and i was hoping to grow some dwarf hairgrass/marsilea hirsuta into a carpet as well as some other low-light plants.

Also, i have read some stuff online about CO2 systems dropping the ph of the aquarium and leading to fish deaths is this something i should be worried about if i use pressurised CO2?
Thanks a lot!!!

 

[Sanctuary80808]

Sorry i forgot to mention that the substrate will be eco-complete and i will also be adding flourish excel (liquid carbon thingy) to the tank

 

[minnnt]

If you choose your plants wisely then there would be no need to run co2. If you use a planted substrate then that will provide enough nutrients. If you dose flourish then you will need to dose tpn+ I think... that's how I understand it anyway. Your lights aren't particularly that powerful so I would go for normal substrate and low demand plants... but that's just me.

Also if you use plant substrate then you may experience an ammonia spike soon after.

 

[james_fish]

You could add liquid carbon rather than co2. I use Seachem Flourish Excel and It seems to be doing a very good job. Just choose your plants wisely

James.

 

[RadaR]

Hello everyone,

Also, i have read some stuff online about CO2 systems dropping the ph of the aquarium and leading to fish deaths

This rarely happens. Folks don't understand why their fish die and blame it on the pH dropping as a result of CO2. They probably just gassed them to death, which if I'm honest happens a lot to folks. It's the main cause of fish death in the planted aquarium.
I know people with roughly a KH reading of "0". They inject CO2 and get a concentration of ~30ppm. No fish deaths. Why? The carbonic acid that is produced when CO2 dissolves in water is not a strong acid at all. The amount of H+ ions is tiny thus barely effects the water in a negative way. You can expect a pH drop of 1 when 30ppm is achieved. This can happen in just a few hours, but you won't find fish dieing because of it though.
People mention pH swings killing their fish all the time. It's not actually the pH itself that kills the fish but the cause of the pH change that kills the fish...if that makes sense. Obviously extreme pHs (<3 or >10) wouldn't be ideal. And some fish are more sensetive to CO2 than others.

60W of t8 over 200litres should not warrant CO2. Plant up heavily with fast growers and to be on the safe side add some floating plants. You're good to go. The fish should provide enough nutrients coupled with a good plant substrate. Water changes don't need to be too frequent but should be done after the lights go out for the day.

If you did inject CO2 or dose liquid carbon then be aware that the nutrient demand of the plants increases massively which means you will need to dose macro and micro nutrients (TPN+ for example) frequently. Water changes also need to be large and weekly in order to cope with the increased metabollic waste produced from the fast-growing plants. This waste can breakdown into ammonia and other nasty things. The pours of the plants can also get blocked, stopping gas exchange.

Low light, non-CO2 tanks don't need too much flow. 5x the volume of the tank turned over every hour is ok.
Tanks with high light and CO2 should have 10x minimum.