It is a S. purpurea. And like the VFT they are not houseplants. 99.9% of the time that someone has a problem with their sarracenia it's because they're growing it indoors. They don't last long indoors. They need 6+ hours of direct outdoor Sun a day minimum and indoor Sun isn't as strong as outdoor. And they need 3-4 months of winter dormancy. Water with distilled water, rainwater or reverse osmosis water only. NO tap water (unless the TDS is below 50ppm) or other bottled waters. Taken care of properly they will multiple easily.

The water in the pitchers probably came from when the nursery was watering them. The water naturally goes into the pitchers and begin pooling in there.

Some places recommend that you would fill the pitchers upon taking it home to its new location, but others suggest that it can be fine without you filling it up, the insects will still be digested just fine.

If it's outside, it will also naturally fill with rain water.

Thanks to you both for the replies. Realise they’re outdoor plants, but in the UK? They’re in an all glass conservatory, temps can and do reach 90-100c in summer.

The VFT had got around 6 traps and one crown when I bought it in spring, now it has many traps and multiple crowns, so something must be ok surely? It also turned bright red in summer, read that’s a good sign also?

The Sarracenia has made several new traps and not lost any since I’ve had it. Another good sign. Both get only rainwater, the S.p gets additional flies as it doesn’t appear to capture any itself.

Do I leave them there for winter, it’s unheated...do I tip the water away...do they still need to be kept moist as Ive read the VFT will lose it’s leaves and go dormant? Can’t find much info...could you direct me to a good source of cultural info please? Sorry for all these questions, I’m new to this type of plant. Thanks in advance.

As the days have gotten short you probably noticed both stop growing. Keep them moist all winter.....at least don't let them dry out completely. they will resume growth (and possibly flower first) when days begin to lengthen in the Spring.

So....did you give it a dormancy period? Mine (outside) are beginning to show signs of new growth. I'm looking forward to flowers soon (for first time as my plants have been 'in ground' for over a year now). It's kinda sad that most of spectacular traps don't color up till late summer though.
New traps on the VFT are starting to form as well. I remember I couldn't believe these were hardy perennials (for my zone at least).

I guess dormancy was forced upon them in the form of a unheated house in a U.K. winter as I unexpectedly had to go away for seven weeks from early Feb. The Venus FT has dwindled as it had to be left to itself which started its demise I’m sure and now its only just alive. It started to sprout several flower stems but I cut them off so as not to weaken the poor thing any further. I removed all the dead and dying leaves/traps and what was left was, and still is, very weak. I unpotted it to check the roots hadn’t rotted and then split it up and set it back in a new gritty sphagnum mix, so we will see how it goes. The Sarracenia also suffered. It had a lot of its pitchers dry up completely so Ive cut them off and both plants are now producing new pitchers again. Thanks for asking.