You are most definitely getting filler in your shot and therefor your circulatory system if your shooting pills thats for sure. Ive heard you guys(Americans that is, hydromorph is very rare here in Australia unfortunately) say that its ok to shoot Dilaudid because it mixes up clear but its most definitely not. You should definitely get your hands on some micron filters even if you have to get them off the net. We are very lucky in that our needle exchanges(most of them anyway) give out micron filters for free, they are an invaluable piece of equipment for IDU's, even if your just shooting street drugs and not pills. I use them when injecting speed/meth, heroin and pills because the blue 0.22um ones filter bacteria as well as particles.
Definitely get your hands on some. When I was addicted to oxy I started using them and very quickly noticed my health and circulation getting better.... Stay safe