Effect of CO2 on New Fish

[Redsedge]

Hi. I’m in the early stages of my first aquascape and, mainly for budgetary reasons, planned to introduce CO2 some time in the future. After reading several threads about the potential adverse effects on livestock by the introduction of CO2 at a later date I’ve decided to get CO2 from the get go. What I’d like some feedback on is if introducing CO2 to a stocked tank may be problematic then surely the same applies when introducing newly purchased fish to a CO2 injected tank if they haven’t been used to that? Apologies if I’m missing something really basic here.

 

[jamiep]

Switch off the CO2 the day before introducing any new fish (and properly acclimate them as usual). Turning it back on the next day and the gradual ~1 degree PH change over the day will be fine

 

[foxfish]

There will always be a risk when using C02, there is an excepted or recommended upper target of 30ppm but more and more folk seem to want to push this limit!
So if you are concerned about your fish, then you can stick to 20-25ppm.
However mistakes can easily happen when you first start out and that is why I repeatedly recommend starting out with a plant only tank until you get the hang of how to adjust the gas to suit your needs.

 

[tiger15]

Run away CO2 (> 50 ppm) is toxic to and will kill fish, which had happened to me by accident when I was a new user of CO2. So make sure you babysit how your new CO2 regulator is operating closely for a few days before leaving it alone. Maintaining CO2 below 30 ppm is safe to all fish, even among my hard water loving African cichlid. However, it’s best to introduce new fish before or after CO2 on so the new fish have chance to acclimate to rising CO2.

 

[PARAGUAY]

Based on my own experience, l would do it on a weekend at least give a couple of days or so to get it set up, generally start with a low energy system first as @foxfish says.

 

[Redsedge]

Thanks for all of the advice. I’ll ensure I get everything settled over a fair period and reduce or turn off immediately before introducing fish. Thanks again.

 

[bazz]

From my experience unless you are preparing a six month plan, stem heavy, IALPC entry then there really isn't any reason to be injecting at the higher end. 15-20 mg/l is enough for most community tanks, the key for me is stability.
At around 15mg/l I've never had a problem adding fish in the morning before the CO2 comes on, the water is fairly well off gassed overnight through the use of a surface skimmer and I do have the luxury of a 60l quarantine tank so early morning transfer is an easy process. If buying and acclimating the same day just turn off the CO2 before you go to LFS and start it up again in the morning.
Using CO2 from the get go will allow you to get it dialed in well before any livestock is added.

 

[Conort2]

Switch off the CO2 the day before introducing any new fish (and properly acclimate them as usual). Turning it back on the next day and the gradual ~1 degree PH change over the day will be fine

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