chishnfips
WHAT! You went over my Helmet!

All the parameters are fine, I have no idea as to why he died.

Ok Update: I phoned my LFS a to ask about what plecos they have in stock and while I was on the phone I told them my dilemma. They said the two reasons why plecos die are mainly these:
1. a toxic build up of waste beneathe the substrate
or
2. starvation
It couldn't have been the first one, as I am always moving stuff and gravel vac the sand, moving it about to avoid this. So it must be starvation, I feel really bad about it. I fed him a large piece of cucumber all the time and an odd wafer aswell, but the lfs told me cucumber doesn't have any nutritional value and I would be better feeding with the likes of potatoes and carrot as they have more nutrients. I feel rotten about it.
They said they have a L066 pleco in stock so I might go and get that they also have a L007 (vampire plec).