Reply To: What to do, What to do?
For what it’s worth, here’s my experience with a couple of issues raised in this thread:
Snails as friends:
I just had 20+ free-swimming CPD fry appear in my tank yesterday (Yeah!!!! I’ll post my conditions in a separate thread). The 10g tank is nearly filled with java moss, and the java moss is swarming with the small cone-shaped live-bearing (Malaysian?) snails. The snails spend most of their time browsing on the java moss without actually eating any of it. I suspect they are sucking off films of bacteria and other microbes. They also keep the hydra population down (I feed microworms to condition the adult CPD, and the pesky hydra catch the excess worms). As far as the eggs/fry go, I worry more about the little green hydra than I do the snails. Also, snail fecal pellets are well known to foster infusoria production. Since the moss is too dense to have seen the eggs before the fry started swimming, I can’t say for sure they didn’t get a few eggs, but I think it unlikely, because of their tendency to congregate within a few short hours around any uneaten food until it is gone — if it is food to them, they find it and eat it.
Snails dying off at a certain size:
I have also experienced this in my tanks that are nearly filled with java moss. My tap water starts out alkaline, but over a couple of weeks, the moss takes out all the nutrients from the water, including calcium. Without calcium the water turns acidic. This nutrient deficiency affects not only algae growth, but also depletes the minerals needed to build snail shells (and when the water turns slightly acidic, the snail shells begin to soften and dissolve — puffer owners know what soft water does to shrimp and snail shells).
Shrimp eating fish eggs:
I have seen reports by killifish breeders that ghost shrimp were observed to “clean” fish eggs — rolling them around in their pinchers and cleaning off any fungus threads that began to grow. The only eggs that were eaten by the shrimp were ones that went cloudy (unfertilized or dead). I don’t know if this would apply to other (amano, cherry, etc.) shrimp or not.
Happy breeding, all!!