I live in the PNW near Seattle, but because it is summertime, nighttime temperatures are consistently above 10 degrees celsius and daytime temperatures are around 27.
It started looking like this several months ago when it prepared to flower and it was still indoors for the winter. I put it outside and the condition kept deteriorating. The fruit also seems to not be getting any bigger.
About nine months ago when I planted it I filled the pot with potting soil and about two months ago my mum covered it with sand to keep water in or something. She raises a lot of houseplants so I assumed she was experienced on this matter.
I water it about every three days with about 250 ml water and a few drops of MiracleGro (it also occasionally rains). I read that to help iron deficiencies people put rusty nails into the soil so I stuck some old screws into the soil.
Is it the sand? I have a sneaking suspicion it is the sand.
The pot has holes in the bottom such that it was possible for soil to trickle out. Should I wait a while without watering and see if it gets better?
With a single plant it’s hard to know. I would cut the watering back to once a week without any additives. Give it a real soaking and let it drain and go dry over the week. Also, as soon as they little pineapple starts to turn yellow at the bottom (or when it smells like pineapple) cut it. It’s not going to get bigger than that, and that will tell the plant to put its energy into roots or a new stalk (pineapples are bromeliads , so they self-propagate). Good luck!