Hi
Newb question. will shrimp kept in a bucket filled with tank water be ok overnight with no heater and no filter?
Much depends on their health when shipped, shipping experience, and then stress levels while in the bucket
Some shrimp species and domestic bloodlines are more/less sensitive
If you do this, use a shallow amount of water, eg, 10cm depth rather than deeper water, eg, 30cm - without a filter or sponge aeration, the only oxygen in bucket water will be from passive diffusion, also any “air” that is trapped in tap water
Avoid using a fine air stone with shrimp as microbubbles may be trapped beneath their exoskeleton (and this seems to be fatal in some instances)
As Darrel mentions, always provide shrimp with something to “cling to” - though I suggest not to buy shrimp from sellers/shops that don’t ship shrimp with suitable materials (Indian Almond Leaf definitely trumps a bit of plastic netting)
If shrimp arrive in cloudy or smelly water, seem lethargic etc, then bucket storage may be the end of them - in this situation a drip acclimation is not recommended, instead transfer shrimp fairly quickly to water of suitable pH, GH, KH etc (often I’ll begin by adding an “overdose” of Prime diluted into my prepared water, as this will immediately bind ammonia, and more slowly bind nitrites/nitrates)
I always test shrimp water quickly with multitest strips, and compare to the water I’ve prepared (also compare to the water conditions previously stated by the seller/shipper)