The link to instabilities is not helpful. The "instability" article is very specialized and hard to understand.
The following sentence needs a change: "But the main message of the experimental study is a surprising similarity in scaling, statistics, and structure of the elastic stresses and passive scalar mixing in elastic turbulence in a finite size vessel, in spite of the important difference in the dynamo effect. " The author may want to repeat here what this important difference is.
What is a "macro vessel"?
It would help the reader, if the author would introduce the concentration and the polymer at the beginning. Is there a minimum concentration for a given polymer to observe elastic turbulence?
When the concentration is mentioned at the end of the article the polymer needs to be specified.
I have taken the liberty of adding a few semantic corrections directly into the paper. Overall this is a very helpful and short article. </review> <review>
The article is very helpful and it exposes clearly the important properties of the concerned phenomena. It might help the reader if the author adds that many properties of the elastic solutions (especially the dilute ones) can be understood on the basis a single polymer dynamics where the polymer experiences the combined action of the stretching by the flow and the elastic relaxation. As applied to the low Re elastic turbulence regime, if the velocity gradient that would exist in the system with no polymers inside is larger than the inverse relaxation time of the polymer, one expects an instability and non-linear dynamics. A reference to Lumley's work on the time criterion seems appropriate in this respect. Finally, there are some semantic problems like in the sentence: "The elastic stress occurred due to polymer stretching by a flow becomes.." </review>
I revised the paper according to the comments of the Reviewer B by adding more text and correcting sentences mentioned by the Reviewer. I did not add the reference to the Lumley's time criterion because in the context of elastic instability and elastic turbulence it is equivalent to Wi number exceeding the critical value. On the other hand, I did add another reference on Lumley in the relation to the coil-stretch transition in polymer dynamics in a random flow and its connection with turbulent drag reduction.