25 pounds is a lot. what are your stats? Unless you're a newb, you shouldn't aim to gain weight so rapidly, as you just cant gain 25 pounds of muscle in 5 weeks. You can gain a lot of water and fat though.
And if you are in a newb in the position to gain that much weight, you shouldn't rely on steroids.
If you are just trying an all-out bulk, have more modest weight gain goals, because you don't want to look like bloated **** at the end... Anyway the best weight gain cycle you can do with "PH" are combinations or bridges involving Superdrol, pheraplex and "tren"