Fish oil is one of the most researched supplements out there and one that the whole team @ Precision Recommend taking. Swing by your local CVS and look at the shelf and you will find many brands to choose from. How do you know if there any good? I have the formula for you that you can find out the purity of the product and know your money is best spent on a quality product.
Take the total fat in thousands so 1.8 would be 1800. Take the EPA and DHA and add those together. Divide the added EPA and DHA to the total fat and you should get a number such as .50 or .33 etc..
An example: Total fat 1.8 g
Over .50 is a good product and one that you will pay more per capsule than one that is less than 50% pure.
We have a good fish oil brand Barleans Ultra that we sell here at Precision Fitness that is 53% Pure.