What the heck are these on my glass?
 

First thing I do every morning is look at my 29g cube tank to see how things are (and sometimes Plectranthias Inermis is still out front hunting, before heading back into the rocks to hide for the day, so I get to see him).

Anyway, this morning I found these flat white blobs all over the upper left front and side walls. After I stopped freaking, I spent about 2 hours on the web looking at pictures but couldn't turn up anything that matches. One of my turbo snails and one fighting conch were in the area. I have seen one or two of these blobs scattered here and there before, and took them off with my mag float when I cleaned the glass.

The cross-section of these things is hard to see, but looks like it's very flat, with a slight raised area in about the middle. I estimate there are about 100 of them and they don't seem to be moving. I've used a sharpie to mark the locations of a couple of them, so I'll see if they move slowly or not at all.

The closeup shows the shape, which is what I haven't been able to match in any of the pictures I've seen. I've combed through online ID guides, nothing there either.

Tested last night, and calcium was 420, mag was 1210, alk was 11.3 (story here: I started dosing with polyplabs One, four days ago after testing params and having them in balance - now alk is out of whack, going to rebalance gradually over the coming week).

Thoughts? Advice? Should I be getting a giant tote of saltwater ready to rescue everything?

Heres a great "critter" guide
http://www.lionfishlair.com/hitchhiker.shtml

Kind of look like what their listing as "pumpkin flatworms" perhaps?

Those are definitely flatworms. They will move, but some species are much more active than others. I'm not sure which species you have - some are predatory mainly to corals, some are prone to plague-like population explosions, and some are harmless. First things first, I'd check very closely that there aren't any on your corals. I'f the corals are clear, I'd keep an eye on their population, and if everything seems ok I'd just ignore them. Of the harmless flatworms, their population will wane and flux, and under normal conditions they aren't usually a problem. If they are on your corals, that's an entirely different matter. If you're noticing their population increasing quickly, that's a different matter too. If they are quite tiny - like 2 mm or so, then they are probably one of the harmless types, though I've had one occasion where a tiny type was infecting a Brain Coral (nothing else). I gave it a couple dips a week apart, and didn't see them again.

how big are they, best bet is to just continuously siphon them out as much as you can with every water change

Add a wrasse, like a yellow/canary wrasse for biological control of flatworms.

+1 for the wrasse. Ive had great success with both my Hawaiian 8 line and my Melenurus. 6 lines may also be good and better suited to your tank size, but I cant attest to them.

Pumpkin flatworms might be it...
 

Thx for that - I checked it out and I think you are right about the pumpkin flatworms. The photos showed them on corals and I don't see that in my tank - yet.

The Feeding Pipette of Death for flatworm control
 

Thank you for the heads-up - I scrutinized all of my corals really carefully, even using the nanoscope and I don't - so far - see anything on them. My bubble coral has been struggling lately and I noticed a few kind of spots on it, but can't match that up with what I see on the glass. I plan to look into whether it's safe to dip the bubble coral and see if anything nasty is shed.

As for size, they are about 2mm in "diameter" and a light pink colour in the brighter light.

On day one, I decided to remove them manually using a feeding pipette (thank you, Canada Corals!). I put tap water into a container to squirt them into, and suctioned them off one by one, getting as many as I could see. They did move when prodded with the tip of the pipette. They were mainly concentrated in the upper left front corner and side wall, and widely scattered when it got to be more than six inches from the corner. So I feel like I got the majority of them - didn't see any of them anywhere outside about a ten-inch distance from that corner.

On day two, they reappeared but this time there were a lot fewer and it didn't take long to remove them.

Day three was today, and I estimate there were only 20 or so.

So we will see what tomorrow brings.

Sucked those suckers off the glass
 

Thank you for this - I decided to manually remove as many as possible. Tomorrow will be the fourth day from when they first appeared and I'm hoping the numbers will be even further reduced.

Will check out wrasses
 

Thanks for the suggestion - I might just check into that. At the moment I have a yellow tail blue damsel who is a jerk. The yellow clown goby perches in the acros to stay safe, the Pygmy hawkfish just minds his own business during the daylight and hunts at night, and the lawnmower Blenny is a lot bigger than the damsel, and actually chased him out of a cave. I'm not sure how the damsel would be with a wrasse and I'm also thinking at the moment I'm fully stocked.

I'll see how things go with the manual removal and take it from there.

Thanks to everyone for the replies - it's great to know there's help out there! 😄

Good plan on the manual removal. Your tank is too small for any type of flatworm-eating wrasse imo. 6-lines usually get really aggressive, and smaller tanks tend to magnify that. Fwiw, you don't need to dip corals in anything other than tank water for flatworms - they blow off easily with a turkey baster.

Pumpkin (I think) flatworm update
 

This morning there were fewer than yesterday but on scrutinizing my corals I noticed the large hammer was mostly retracted and was horrified to see the exposed base flesh had the dreaded beige dots on it. 😱

Taking Myka's advice, I got the trusty baster and was able to remove a bunch of them. After I got whatever I could (it's in a hard-to-reach spot) I used the baster to fluff a bunch of water all around it and they started flying off in all directions! So there were lots of them. I also fluffed water at my bubble coral but nothing came off it, which is a relief. Might be a temporary relief, but I'll take it for now.

My plan now is to remove whatever I see on the glass every day and keep fluffing water around anything that looks even slightly in distress. I will also adjust my jeboa wave thing so the area around the hammer gets increased flow and see if that helps at all.

And I expect I will be dealing with more, when the eggs, if any, hatch.

The other thing I need to do is figure out whether parameters, nutrients, light, temp - any of these - are in a range that encourages growth and reproduction of these things. If there's something I can change that impacts only the flatworms, I'll do that.

Sigh. It's a journey...

If you knew you could catch it, Id totally ad a wrasse for temporary pest control.

I recently had a bout with flatworms. I picked up some stuff called Flatworm exit and some carbon and gave the tank two doses over a few weeks time. Worked great! Knock on wood, so far I have not seen anything come back. Amazing how many there are you can't see and where they came out of. Good luck!

Flatworms seem all gone now...
 

Well it took a while but it's been four days now since I have seen any of what looked like pumpkin flatworms on the glass. The bubble coral looks a bit better and the hammers are opening.

I'll keep watching and hope they don't return in any great numbers.

Thx all for the suggestions!