Tiny Worm/Slug

[Kasrift]

I have a few of these strange slug things. They tend to hand around on the sand, but will occasionally go up the lower glass. Attached is a picture and a video using a magnifying glass. I thought they looked like the ones in this post https://www.reef2reef.com/threads/strange-slug-worm-thing.322309/ so I'm hoping the answer is not the same that it is a flatworm. Looks more snail like, but has no shell. From the top, it's head looks black, but it isn't pointed like a flatworm. Any ideas on what it might be?

 

[Kasrift]

I have a few of these strange slug things. They tend to hand around on the sand, but will occasionally go up the lower glass. Attached is a picture and a video using a magnifying glass. I thought they looked like the ones in this post https://www.reef2reef.com/threads/strange-slug-worm-thing.322309/ so I'm hoping the answer is not the same that it is a flatworm. Looks more snail like, but has no shell. From the top, it's head looks black, but it isn't pointed like a flatworm. Any ideas on what it might be?

 

[Pineapplereef]

I'm going for baby planaria flatworm

 

[Kasrift]

I'm going for baby planaria flatworm

Is it harmless? I try to suck them up whenever I see them, and they are fairly infrequent (like 7 on the sand bed that are visible if I look really hard). Most of the info I see is on red planaria flatworms, or the white ones have forked tails, which these don't.

 

[Pineapplereef]

Sorry, I mis-typed. I meant polyclad baby. However, if you find them now and again with no issue, maybe I'm wrong

 

[Kasrift]

Any other opinions, here is a video of it getting to the sand and you can see it has a black back. The arm to the left is a micro brittle star

 

[Kasrift]

Bumping this up for more opinions. I took a top down video through a magnifying glass in a small cup of it moving. I pulled several out with a pipette and experimented with stuff to kill them. This one in this cup sat in about an one oz of water with a full drop of Salifert flatworm exit for about two hours and didn't care. The same thing for one in CoralRx and one more in Polyplab Reef Primer. None seemed to care. I'd love to identify it to know what it is, as mentioned I don't have a ton of them, but I did lose a blasto and a bowernlbanki and these were crawling on them. I had the bowerbamnki for about eight months and the blasto for about six months.

Parameters in case people are wondering are as follows as of this moment (did a water change to use some of the water I pulled for my experiments and dipping/adding coral today):

Salinity 1.025 - checked with a refractometer
Temp 78 - inkbird controller set to 77 with a fan for cooling
Calcium 470 - Salifert test
Magnesium 1350 - Aquaforest test
Alkalinity 7.6 - Hanna checker
Phosphate.08 - Hanna checker
Nitrates low - I just use API checker for this. They tend to run low and I compensate by feeding, but it never shows color past 5-10 range.
Salt Tropic Marin Bio Actif
Kamoer ATO and Wifi Doser with Tropic Marin All For Reef dosed over a 12 hour light cycle period and dialed in to maintain Alk
Tank 32.5 gallon Fluval Flex with inTank Media baskets with chemipure Blue, seachem Matrix, and filter Floss for one side, and same except for a small bag of purigen on the other instead of chemipure Blue. Red sea wave maker and Nero 3, fluval PS1 Protein Skimmer, both fluval lights and a 21led reef bar pro on a current USA mount(waiting for my noopsyches as we speak). Tank is a mixed reef with some Sps up top and a pokemon collection of like one of everything below (picture for reference).

 

[Kasrift]

Btw, water is only murky because of the water change and Tropic Marin Bio Actif salt always takes a moment to settle in even if it was mixing for hours. It just adds and looks foggy for a couple of hours.