How To Get Enough O2 For Fish And Co2 For Plants

[rsands]

How do you know you have the balance and would plants put enough oxygen into the water or do i need an airstone as well to help fish (once i buy them)?

 

[nry]

Adding CO2 does not alter oxygen levels (unless you add too much CO2 and it causes problems). The best method of ensuring you are adding a suitable level of CO2 (30ppm is suggested as ideal) is to use a drop checker alongside some 4dkh water and the correct type of pH test kit fluid: the drop checker should be green to indicate ~30ppm, blue is not enough CO2 and yellow is too much CO2.

Adding an airstone alongside CO2 will generally be a bad thing as the water surface agitation caused by the bubbles from the airstone is enough to drive CO2 out of the water very quickly making it unavailable to the plants.

 

[Azaezl]

Something I've been doing as I'm paranoid about putting too much co2 in and not having enough oxygen for the fish is turning the airstone on when the lights are off.

 

[RadaR]

I second what nry said.
Hopefully having healthy plants and the addition of CO2 should result in some pearling, providing oxygen for the fish.

 

[rsands]

thanks for the replies. so basically at lights out i could turn the airstone on for 6 or 7 hours during the night? And then have it turn off an hour before lights on?

I take it that would help give a good balance? And could i then inject the CO2 during the day for the plants?


cause i am about to start injecting CO2 and i dont want to much injected CO2 and then no oxygen for plants as i have no airstone on at all?

 

[RadaR]

Yes
Make sure you stick to that routine though and don't fluctuate it too much.

 

[rsands]

No problem. I am away to buy two timers and set them in that strict routine

 

[George Farmer]

No need for an airstone at night unless you are overstocked with fish and have minimal surface movement.

24/7 CO2 is fine providing there's good surface movement and sensible stocking levels.

Many use a solenoid linked to the lights to save CO2 on a pressurized system.

 

[rsands]

the surface movement is caused by the fluval 305 filter outlet just waving it up and down. would that be enough?