I'm struggling to find guidance on a few things; hope you can help. First, some specs:
44 gallon tank (about five weeks old)
Injected CO2 (on a timer/solenoid)
Eheim Cannister Filter
45 GPH Powerhead
Lots of Wood & Plants (mostly stem)
Light-to_medium Bio Load
I mention that stuff only because I think it may be relevant (or not). Here's the deal:
In the last few weeks, I feel like I have gotten the CO2 dialed-in, which is to say that I haven't been seeing the fish doing massive O2 bong hits at the surface, or going for oxygen, and it's also to say that it looks like the plants are getting what they need in gas quantity/distribution. And the Drop Checker has that color of green that looks--visually--the way it should. Not yellow; not blue. Green. But, in the last few days, I've noticed the fish (ember tetras/lemon tetras) gasping for O2, but only in the morning, when I wake up. Note: there is currently very little surface agitation; neither the filter outflow lily pipe nor the powerhead move the water up top more than just a ripple.
The first time I saw that, I did a >20% water change, added more Prime, and that seemed to have fixed it. I've also tried playing around w/ the powerhead, hoping that water flow or current might help in some way. But I want to learn more about how best to find the 'goldilocks' zone, where the fish and happy and healthy, the plants get gas, and there are no 'issues'. Sadly, I've had trouble finding useful or consistent info in forums, or the usual places.
Should I just turn down the CO2, at the expense of the plants? I'd hate to do that as I have a minor algae problem, and I think the CO2 level is actually a bit low, anyway, given the Drop Checker color.
Should I mess with the powerhead again to increase surface agitation? If so, will that cause the CO2 to decrease, at the expense of increased O2?
Should I strive for a general increase in surface agitation?
Thanks in advance for any useful info on this matter.