More oxygen required

[Gfish]

Hi all,
I have a tank that is planted fairly heavily now, with anubias, ferns, crypts and some apogoneston and crinum. I have CO2 injection and I dose dry salts mix.
Things are going ok but if it's at all possible I'd like more oxygen in the water. I know that plants produce it, but in the past when I put a spraybar across the surface which kicked out bubbles into the tank, within a very short space in time, my fish seemed to thrive! The fish I keep are Geophagus cichlids, Pindare to be precise. Alot of the time the fish breathe fast. And with the last batch of Geos I had, once I made this adjustment and improved oxygenation, their breathing slowed and fin extensions grew longer very quickly.
So is there a way of doing this without losing CO2 from the water column?????
Cheers
Gavin

 

[Arana]

just run a small airpump and airstone on a timer switch once the lights have gone off

 

[Gfish]

Hi
Yes I can do that, and my hope is that there's still oxygen in the water through the first few hours of the lighting period. This is when the fish seem to breathe heavily most. I'm not sure how long oxygen will hold in the water once the airpump is switched off???
Thanks

 

[G H Nelson]

Hi Gfish
Are you using a drop checker?What colour is it?
If its Limeade colour in the morning there's to much Co2 that's why your fish are breathing heavily
I suspect that you have a large fish stock as well...or largish fish.
These are two things that you can do cut-back on your Co2....so that your checker is Green.
This may help your fish stocks respiration.
Or use a air stone through the night and monitor the colour of the drop checker in the morning if its Blue cut back 1 hour...do this each time till it becomes Green.
That may help.
You will be surprised how much Oxygen plants up-take during the night....especially if its a fully planted tank.
Regards
hoggie

 

[Fred Dulley]

Lots of folks worry about O2 way too much.
It's also worth considering that high CO2 doesn't mean low O2. Nor does high O2 mean low CO2. In a planted tank we strive for good levels of both.
Ensure CO2 isnt too high and make sure it is being distributed well throughout the tank.
Some water movement is good for surface gas exchange. A ripple is fine, but nothing that "breaks" the surface.

 

[Gfish]

Thanks Gents, lots of things to think about now. My lights come on at 3pm so I've had CO2 starting 2 or 2.5 hours before this. And I've been aiming for yellowy green on the drop checker as the lights come on. Maybe I'd be better off with it slightly less and just be happier with green at the start and throughout the period of lighting.
On thinking of this, most folk aiming for yellowy green at the start probably have a tankful of plants with many fast growing stems. My tank has no fast growers at all so it may be silly to have so much CO2 in the water and be better to aim for green which is probably more than enough for slow growing plants. What do you think?

Good to hear it's possible to have high O2 irrespective of CO2 level. I'd like to optimise O2 levels in the tank so airstones at night, and the tank having a ripple during the lighting period.

My CO2 enters the tank through a filter and spraybar. What's to stop me doing similar and positioning an airstone under the other intake so my second output is firing water with heavily dissolved oxygen in it? Would this work? And does water get to where the oxygen is so well dissolved? And this still benefit the fish?

Thanks