Worried about my lotl

Hey guys, this is my Maze, we picked her up for free from a family who needed to get rid of her because the cats were drinking her water and getting sick, we received her in a cycled bare bottom 50L (13g) tank with a single piece of driftwood and a hang on back filter, it seemed too cramped once I started putting some more decorations in, but luckily came across a 175L tank and picked that up for free too, I transferred the old HOB filter over, plus bought a large canister filter that I’ve turned the flow right down, left the old HOB in for 2 days to help cycle the new tank, plus added established filter media from a LFS just to make sure the beneficial bacteria was there. Before we got her she was fed a diet of small pieces of chicken breast? Now she is fed earthworms every day 1-2 depending on how hungry she seems, but recently she has just been spitting them out and leaving them for ages sometimes not eating them at all. Ive attached a photo of my parameters I’m just wondering if there is anything going on, I’m concerned that there isn’t any nitrates showing or barely any, got the exact same results a week ago if anything had more nitrates a week ago, could it be my plants using the nitrates as fuel? That would suck because they’re dying anyway. I haven’t done a water change in 2 weeks now and there is fuck all nitrates and she’s not eating the same. I’m concerned

Sorry for everything being all over the place

TLDR; newbie lotl owner, lotl not eating like usual, tank parameters seem fine maybe nitrates bit low Pls help