Assuming you are talking about cherry or bee shrimp, as long as they don't get really cold -as in under 45 degrees -they'll be fine. I keep several unheated shrimp tanks in a colder house than that (your tanks will usually be 3ish degrees below room temp if lighting, etc. doesn't raise it) and the tanks I do put heaters on are only set to 73 degrees. Too warm is a much bigger threat than too cool for most dwarf shrimp species you would likely be considering.

 

Yea cherry shrimp was the plan. Are most plants ok at this temp? I was looking at rotala rotundifolia and it said keep it above 70 degrees.

 

All of my tanks are planted, and a few have various Rotala. Growth may be slowed, but they sure seem to do okay.

 

I hang several planted bowels with cherry shrimp by the window with zero tech (no heater, filter, aeration or light). The room is heated and AC. I worry more about summer heat than winter cold with temp dropping to 65F in winter nights and up to 88F in the summer afternoon under direct sunlight. Shrimp are doing fine but don't breed in winter. Floating plants like frobit, salvia, and carpet plants like DHG and Sagittaria are filling up, but stem plants like rotala and ludwigia are hardly growing due to lack of CO2.

 

I'd be so horrified of those popping/ripping off but I'm happy to see someone NOT putting a goldfish in one of those.

Whats your substrate?

 

I have a small shrimp bowl- it's a gallon and a half, unheated with a bit of water circulation (airstone). It gets low as 64 at night in winter. My amano shrimps do fine with that, but not all the plants do. Of the plants I tried in unheated tank (my 33L is also unheated), these do great for me: buces, anubias, elodea, greater duckweed, many kinds of crypts. These do just okay: subwassertang, mermaid weed, rotala stems. Windelov fern, java fern, moss, vallisneria and hygro struggle. But your conditions of course are going to be different and I don't know if temperature alone is why some of my plants don't do well in there.

 

I have Java fern in an outdoor pond that freezes over at times in the winter and come spring their just fine so a bowl in your cool house would be no problem.