Gasping, thoughts please

[Def]

Hey guys.

Woke up this morning to find my platies and 2 generations of platy fry (about 30 fish in total) at the surface apparently gasping. Gill movement seems quite rapid. Just to be sure I did a quick water test before leaving, ammonia 0, nitrite 0, nitrate about 10. Did a scheduled water change last night anyway.

Last week I added one of the Nutrafin CO2 injection/diffuser systems. It took a while to get started, and the regular bubbles have just started appearing in the last 2 days.

I'm concerned that the CO2 system has contributed to a lack of dissolved oxygen in the water, causing the gasping. So before I left I disconnected the CO2 line into the diffuser and left it sitting outside the tank (didn't want to dump the mix in the canister yet). I ran my finger round the inside of my fluval to make sure the output nozzle was clear, and moved the output volume/strength slider up a notch (that'll annoy the fish, but at least it will get even more water moving). Also aimed the output towards the middle of the tank rather than along the back.

Can anyone see a flaw in my plan/thoughts? Anything else it might be? If they're still gasping when I get back home, what can I do next? I don't think it's parasites etc, it affected all the fish far too fast and I couldn't see anything on them last night. They've never gasped like this before, only the very rare pop to the surface then swim back down that platies do...

And if it is the CO2 system, why is that causing a lack of oxygen... I have the diffuser point set at the level for a tank size smaller than mine, mainly because I don't have a densely planted tank but do have some big individual plants. I would like to keep the system

 

[Angry_Platy]

I would say it is the addition of CO2.....since this drives off oxygen.....that is the challenge, providing enough carbon dioxide for the plants yet enough oxygen for the fish....

I hope your fish are OK when you get home

 

[Timmy]

No specific suggestions, but you can get oxygen test kits - probably worth getting one.

 

[Def]

thanks for the suggestions, I'll get an O2 test later on. I'm hoping by the time I get home the water should be far more oxygenated... 9 hours with a fluval on high should create plenty of gaseous exchange.

Any other ideas?

Once this crisis is over, I'll have to look closely at that CO2 system. There's no way I'm putting my fish through this again just for the plants.

 

[Def]

Got home, they're all fine. Phew.

Looks like that CO2 reactor is going on eBay, unless anyone here wants it?