I bought an aquamedic sp3000 dosing pump secondhand and it is not working. The motor turns round, but does not pinch the tubing sufficiently to draw any liquid through at all. So I am going to have a go at servicing\fixing\modding it as follows... - New tubing (apprx Â£6 per\m on ebay. Unless someone has a reel of neoprone\santoprone spare and does not mind sending me a few inches...) - wrap pvc tape around the rollers to increase their size and therefore contact pressure with the tubing. - vaseline around the tubing\roller\rotating area (will this work, or should I buy some grease?) Hopefully that will be enough to bring it back into service. Some reefers use normal airline tubing and just replace it more often so I may eperiment with that before ordering the proper stuff. I have also found that the roller assembly moves erratically - it catches briefly every half revolution, then jerks forward, like it is snagging on something. I will take it apart and have a closer look, but for now wondered if this is normal for this pump (does not seem normal to me). I also have a pump bought off ebay that has no housing, so if I can not get the aquamedic working it may get cannablised and wind up as a very expensive casing for the other pump Any comments welcome.