Originally Posted by dwalstad
Interesting. Since the pH and water is the same in both tank halves, pH doesn't really matter. There's also no need for fish.
You will have plenty of other confounds and wiggle room in your reporting, so I would keep it simple and do it as a "pilot experiment." If you get a dramatic difference, then you can trumpet your results and we can enjoy hearing about the details and speculations.
If you get no effect, then I could point to not doing experiment in triplicate. Or that both tank halves were exposed to light at some point during each 24 hr cycle. In the published experiment, there was light in each case, but one set had normal light, the other light where all the shorter, more energetic wavelengths (below 520 nm), which create reduced, algae-stimulating iron, had been removed. Algae didn't grow with the shorter wavelengths, but it did with normal unrestricted light.
I agree that this will not prove anything, but I'm just looking to see if, in a normal planted aquarium setting, does big differences in how iron is dosed cause a big difference in algae problems. It has to be a big difference to mean anything at all for me because I find it very hard even with this set-up to get two tanks to act the same. So, the first step has to be finding out just how much variance is "normal". I have no idea what I will find out, other than that the odds are that I won't see any significant difference.
The reason for the two fish is to have something else to enjoy with this odd tank. I will really be embarrassed if one fish survives and the other gets sick.
I enjoy doing this kind of thing!