David W. A.

Ok... I have massive pearling (finally), at least very good pearling, but all my fish are listless and lathargic *during* the peak pearling hours. My PH is below my high range test kit, but I would guess the ph is about 5.8 based on it is about 2 grades of yellow below the 6.2 on the test strip.

Evidence of pearling - lotus plants, so many bubble some leaves *flute* up.





What do I do? I thought that I would have massive O2 under these conditions. Is it the PH drop?

120gal, 390watts, 6 to 8 bubbles per second pressurized C02 into home made reactor, EI ferts. 2 days after a 50/50 water change.

BryceM

Um, when I see pearling like that, stuck to the plants, it's often coming from algae - but that's beside the point.

If your CO2 levels are too high, no quantity of oxygen in the water will save your fish. The plants will love it though. A pH reading doesn't tell you a dang thing by itself.

Best method - take some tank water and leave an airstone in it for several hours to bring it to equilibrium with the atmosphere. Read the pH. Aim for about a 1.0 pH drop from this number. This will give you a good concentration of CO2 almost every time, regardless of your water chemistry.

People make too much of pearling. To get it you need a large plant mass, good light, proper ferts, healthy plants, few fish, and relatively little surface disturbance. You can have perfectly rapid plant growth without pearling. You can also have pearling in water that will be lethal to your fish.

fresh_newby

My guess is your CO2 is too high. Your fish should never be lethargic in a planted tank. You don't need pearling like that to show plant growth. As long as you see O2 outgassing of some sort, that is enough.