crypto currency day trading?

You absolutely can, but you need to stay committed to it. It's incredibly similar to day trading on the stock market, you need to stay vigilant and watch everything you can.
I used to day trade cryptocurrencies about two or three years ago to make more money off of mining. I would mine an alternate coin I thought would increase in value, and I 'd trade it around with other alternate coins until I could make my way up to a fair amount of BTC. I often doubled, tripled, and sometimes even quadrupled the amount that I had made from mining. Of course, it was never a large amount but if you can do it with small margins it's absolutely possible to do it in large trades.
To give an idea, I probably made about $50 every time I would trade up to BTC. I would trade through up to 10 different coins and would eventually trade it into BTC once I was satisfied with the return.