Sure there are, Shrimp would be my choice in smaller tanks along with snails.I am planing to breed my bettas again but my tanks keep growing algae.Is there any algae eating fish or invertebrates that can eat algae without harming the fry?
Might try some mesh screen over tanks ,or move them to location that see's less sunlight ?I only breed my bettas outside so maybe it is the sunlight causing the problem.
Thanks.