How many ghost shrimp?

[Hybridfish7]

I wanted to add some life to my mosquitofish tank, (as if mosquitofish weren't lively enough,) but I wanted to get some ghost shrimp as well.
now, my lfs has a thing where they can only sell 40 at a time, my guess is just so people don't buy everything and go, but that was my plan. their pricing on it is 4 for $1, so I was thinking of going in with 10 bucks and buying a bunch of shrimp. that would give me some room for error in terms of mosquitofish eating them or weaker shrimp dying off upon introduction to the tank, as even if 8 get eaten and 7 die i still have 25 shrimp that would quickly repopulate the tank.
but my main concern is tank size and bioload- it's a planted 20 long with a pothos, hornwort, and duckweed to help with nitrates, but i wasn't sure if 40 ghost shrimp would shock the tank or not. there are already 12 full grown eastern mosquitofish in there.

 

[sikoko]

With a 20 long I dont see an issue. You could always keep some aside in your qt tank and see how things go

 

[AaronKWolfe]

Keep in mind they also do need some salt in their water

 

[johnnymax]

I had that many in a 25 with more fish than you have. I started with about 10 and next thing you know I had at least 50 ghost shrimp. I caught mine in my pond.
When I had my pond dug, that was one of the first things I stocked it with. I went to a state park armed with my dip net and caught a bunch of ghost shrimp and mosquito fish.
I released them in my pond.
You will be surprised, because those 40 ghost shrimp will almost disappear in your tank.
I have a shrimp tank still. It is populated with ghost, cherry and almono shrimp and a snail or two.
I love to see people with a native stocked tank!