Just went to do my weekly water change and noticed that the down pipe from the main tank to the sump was leaking at the joint, only just touched the pipe slightly and it fell off. Luckily the return pump was off but if this had happened whilst I wasn't at home, my bedroom would have been flooded, again ! Can't see why this happened, the joint was solvent welded together and then sealed with silicone on the outside. Not sure what to do now, I can't let this happen again, don't know if i can risk just solvent welding it again. I'm going on holiday in a month so really need to get a permanent solution. Is there any other options, can you buy pipe that fit together without solvent welding them, or am I just not doing it right?