Any new growth is a good sign, so you're doing well with them. I do increase water and fertilizer a bit if the temperatures are high, and we hear you've been having a pretty warm summer there in Jolly Olde England. My Phals put on lots of growth through the summer here even though they really like the cooler temps better.
There's a little white spot under one leaf in your last picture. You might want to check with a magnifying glass to make sure it's not a mealybug. They really love Phals and are hard to get rid of if you let an infestation get going.
