Greetings, and welcome to the community.
I like to use a Fluval Edge vac in a smaller / shrimp tank. Like this one
It is narrow and makes cleaning easier. Sucks out less water volume also since it is thin.
You can do one small spot in the substrate each water change, and lessen the impact possibility of a mini cycle.
One thing to also consider is the type of food you are feeding, allowing excess fillers to end up causing more mulm.
And the quantity of food per feeding, as well as how frequent your feedings are.
Higher quality foods contain less fillers and bulk, which means less poop/mulm. More use of the higher quality ingredients for a healthier tank and shrimp too.
You can buy sampler packs of well known shrimp foods and try out different types which most shrimp love. Changing over foods gradually.