I bought 3 1.5 gallon tanks from Petco last yr. that have small filters and lights with them for around 6.00 dollars each. I know that I could put a betta in each one but I was wondering if there are any shrimp or crabs, etc that could be put in them without cycling these tanks. I have had bettas in them in the past and I usually have been very religious about changing the water about every 3 days so this wouldn't be any hardship at all. My daughter was wanting a dwarf frog and I know they are quite small, just didn't know if anything was available to go into these except for bettas. Thanks.