Last night I was working with twitter open in another window and I hadn't clicked over for about an hour and I noticed I had 423 new tweets.
I honestly don't know when the traffic is heaviest on my feed, I am sure I could find out (if you know how, leave a comment). In one hour last night I had over 400 tweets and I only follow slightly more than 600 people. That is a huge amount of information. I read 3 of those tweets in that group of 423. As for the others I don't worry about them. The main reason for this is that I never try to read all of the tweets that come in, I use curation tools to help me read and recognize the ones that will be most relevant to me.
Curation is one of the keys to avoiding overload on twitter. There are many apps that can use your twitter stream as a primary source and collect information based on the searches you set up.
Right now I have 2 favorites for curation, one that I read and the other that I share because it reflects the SM work I am doing in an attractive way.
I read my Paper.li newsletter. Paper.li creates a daily summary of articles from my twitter stream while also picking up stories from G+, FB, and even Google Search.
The next Curator I enjoy is a recent find for me Rebelmouse. This site creates a "social media front page." This auto-updates to include my blog posts, tweets I have sent, articles I have liked. There is even a blog function so I can add items directly to this page. Rebelmouse found me during an #edchat and invited me to try the platform. I love the look of it and I like the idea of a "frontpage" like a SM calling card. Instead of sending someone to my G+, my Twitter, and my FB. I can send them a like to my Rebelmouse page.
These tools allow me to find quality content while not becoming overwhelmed, and this allows me to relax and learn. (and learning is living)