Hi, so I recently purchased around 15 red cherry shrimp for my 4 gallon tank. I am worried the current from the Elite Mini Underwater filter I have is too strong for them. They seem to be a lot more active when I shut it off. When it's on, they are primarily all down on the substrate, whereas when it's off they swim everywhere. Would I be better off without the filter? The tank has a bunch of floating Salvinia Natans, about 20 leaves of Java Fern and I am growing in some Java Moss. I kind of hope that the plants can act as a natural filter as I enjoy seeing the shrimp swim around -Thank you.