BBA woes (from tanksalot)

[dpatte]

to prevent a ph crash at night when my CO2 was being produced but none being consumed, I added a filter to disturb the water surface.

It comes on when my lights go off and goes off before they come back on in the morning. This helps more CO2 outgas at night.

This is easier to control (timer) than trying to figure out how to turn off a DIY CO2 generator at night for me.

[BigDaddy]

I've never heard of the co2 being that high to cause fish stress.  I think thats an old wives tale.

I had it happen art.  I was using a receipe I had started using during the winter.

In the summer, my non-airconditioned house was very warm.  So was my DIY CO2 generator.  The added heat increased CO2 production.  One morning, my fish were all just hanging out at the bottom, very lethargic.  Measured my CO2, it was at 60ppm.

I immeidately put a couple of airstones in to outgas.... within an hour the fish had pepped up again.

I've had ph's less than 6 and my fish never exhibited those symptoms or appeared to be stressed.

But what was your kH reading at the time?  Anything under 2 degrees would be 45ppm or less... which in the short term probably isn't an issue.  At 2 or higher you are looking at 60ppm... and my fish (tetras, rams, keyholes) had visible signs at 60ppm.

[artw]

around 5-6

[BigDaddy]

around 5-6

Wow!  150 to 180ppm.  Your fish must not exhale a lot of CO2  :shock:

[tanksalot]

I'd always read to turn off the CO2 at night, I didn't know anyone left it on. hmmm interesting. I am nervous of the risk though, I'd hate to see my Atums gasping (yikes!)

Thanks alot BigDaddy for explaining this all to me!! The KH didn't change that much between the two tests (10 mg/L), maybe its the fault of the tester (me) squeezing the bottle of drops.

Could someone give me the formula for calculating CO2 ?

Dave, to turn off DIY I just pull the airline off the connector from the pop bottles.

[BigDaddy]

The formula for calculating CO2 is:

CO2 (in PPM) = 3 * KH * 10( 7-pH )

The easier thing to do is go to Chuck Gadd's page here:

http://www.csd.net/~cgadd/aqua/art_plant_co2chart.htm

There is an online calculator as well as a full chart of pH kH ranges.

He also has a Windows app that does CO2 and nutrient dosing calculations... very handy!

[artw]

the amount of co2 in your water does not displace the amount of o2 ordinarily available at any given time.
IE even if there was 180ppm of co2 in some water there is still x ppm of o2 able to sustain life

[BigDaddy]

the amount of co2 in your water does not displace the amount of o2 ordinarily available at any given time.
IE even if there was 180ppm of co2 in some water there is still x ppm of o2 able to sustain life

It doesn't matter how much O2 is in the tank.  Too much CO2 can still kill fish.  If the concentration of CO2 in the water is too high, then the gills simply can not expel CO2 from the blood stream through the gill membrane.

Don't forget, CO2 in the blood attaches to the same spot on hemoglobin molecules as O2 does.  If the blood is full of CO2, there is nothing for the O2 to bind to.  End result:  The fish asphyxiates.

[tanksalot]

Thanks VERY much BigDaddy!! What a neat calculator on that website! It's a good day for reading up on this stuff in between catching hurricane water :-)

[BigDaddy]

Yes... Chuck's articles are very well written and very informative.