Hmm, interesting, Frugalfish, glad to see the update. I'm not agreeing or disagreeing with your possible conclusion, but rather, wanted to balance this out by expressing that I've observed and experienced the opposite.
Early in my Cherry shrimp ownership, they did not get directly fed, though they *might have picked up a few pieces of fish food (though I've never seen them do so) from when I've fed the Bamboo shrimp, which is only every four days. I've thrown in a wafer before, which they've ignored at the time. Yet they've grown into 60+ shrimp. It hasn't been until very recently that I've started using algae wafers - simply because they're beginning to outstrip my algae supply. Please check out this thread:
viewtopic.php?t=775 It's another example of shrimp eating only algae/biofilm.
Now, my experience with shrimping is still less than a year. But please check out this thread:
viewtopic.php?t=708 In that is a quote from Mustafa, who I know has many many years of experience: "Shrimp do not "need" calcium supplementation at all."
I know that some form of calcium is why some people go out of their way to feed manufactured food, but I wonder if it's something that's "truly" necessary. Where I *may agree with manufactured food, is perhaps - just perhaps there is additional matter they eat in the wild that are not found in the hobby aquaria, be it micropic bits of dead insect or something of which I don't know about (which is why we encourage leaving some molted exoskeleton in the aquarium). In that sense, perhaps the manufactured foods offer trace amounts of possible nutrients they could benefit from using?
frugalfish wrote:Actually they are doing too well as I now once again have an exploding population. The change in feeding is the only one I made, so unless it was a fluke this is my best guess as to what may have caused my losses.
My comment is that stimulation from extra food/change in diet or water parameters (some of which is not always considered good) does tend to cause molting which in turn creates a situation for pregnancy. A simple law is if there is food readily available, procreation happens.
Getting back to the point, I've had 3 deaths since directly starting to feed them BUT my conclusion isn't that the supplemental food is bad, rather, it's the water parameters. And I guess I could say food can be a contributor to water quality going south. I've concluded from reading threads and my general experience that a glitch in water parameters tends to be the number one fault in shrimp deaths. I've no proof or anything, it's just my opinion.
I try to look for visible signs of stress on my shrimp rather than merely depending on test kits which sometimes don't show anything amiss, and sometimes, if I understand this correctly, water parameters can flunctuate during each 24 hours and you may not catch it. So if I see my shrimp racing around the tank or any deaths, whether tests show anything or not, I'll usually suspect something's wrong with the water first, including temperature and try to fix it if I can. Not always, but a small water change is usually what helps, which points back to water quality. Of course a small water change won't help if the water you're putting in is bad, or if the offending cause is still inside the tank.
Again, your theory may be correct; just that my personal experience has not yet supported that algae and bits of biofilm isn't enough for algae-eating shrimp.
-GB