I would like to sous vide a 3lb sirlion roast; i tested my crock pot and it maintains a temperature of 130. Is that hot enough? Seems too low; perhaps if I browned afterward I could bring the temp up to 145 while still having it be tender? How long would I have to leave the roast in the pot to get it up to 130? If I used a big pot and a candy thermometer, what time and temp should I use?