"Zack Robertson" wrote:

After my most recent weekly water change (approx 15%), I noticed that for
the first 5 or so hours after the water change my plants pearl.

BTW - no CO2, no fertilization

Grrr. I want pearling!

The only time I've seen any visible O2 production in my heavily
planted 20 gallon was from a damaged Anubias leaf.

I've got 56 watts of compact fluorescent light, fertilize regularly,
Flourite substrate, and currently my CO2 levels are very high - pH 7.0
and kH 18.5 works out to about 55 ppm CO2. Should be pearling at least
somewhat.

As for the high CO2, that's new. Usually I'm struggling to get it into
the 20s range. I noticed earlier today, several hours after putting a
new DIY bottle on, that the bubbles in the Hagen diffuser weren't
shrinking as they rose. Since so many hours had passed I suspected
that maybe the CO2 levels were approaching saturation, and tested the
pH and kH.

Since according to Chucks this level of CO2 could be dangerous for the
fish (though they don't appear to be in any distress) I've redirected
the filter return flow to increase surface agitation, both to reduce
CO2 and increase oxygen exchange.


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