Question
I have a 20g fish tank, dimensions are around 18in high, 24in length, 12in wide. Currently it contains 7 neon tetras, a plastic column, and a plastic plant (medium size, about as tall as the tank and around 6 inch diameter base).
I'm looking to get some more creatures for my tank, and have been looking at ghost shrimp. Can I add them? According to this calculator, I'm perfectly fine with a 1:1 ratio of ghost shrimp to neon tetras.
However, is that healthy for both the tetras and ghost shrimp? Should I try to have a 2:1 with more tetras than shrimp, or does it not really matter?
Answer
I don't have any experience with ghost shrimp, but I do have cherry shrimps. And it seems like they are pretty much alike in behaviour, size, care taking, ...
Shrimp are a lot different than fish, their bio footprint is a lot lower, they are a lot smaller,... So I would not use such calculators to see how many you can have. They usually just take the size of the fish and do some calculations (which is not a good way anyway).
This site seems to have some good information about ghost shrimp and it mentions 10 shrimp/gallon.
But I agree with Karl's comment above: it doesn't really matter. But make sure you have more shrimp than tetra's.
Actually I would say: the more shrimp the better.
I've got a 30 litre (8 gallon) tank with only cherry shrimp. I started with about 20 shrimp I believe (1.5 year ago). Now I probably have close to 100. But I don't have the feeling it is overstocked. They're always spread out over the tank or swimming around. It's only when I feed them that they all come to the same place and you actually see how many there are.
I also have a 180 litres (47 gallon) tank with some corrydoras, tetra's and a betta in which I added about 15 shrimp a couple of months ago.
I have no idea how many shrimp I have now (lot's of hiding places), but I always have about 10 in sight. So I'm sure those 15 shrimp were enough to keep the population steady (and growing).
So for you, it would start with at least 10-15 shrimp and see how it goes. And I would not worry too much about having to do population control. More baby shrimp will also mean that more will be eaten by the tetra's anyway (becasue they will be easier to spot by them).
Answered By - Diether