Clownfish Concern

[Seafeather]

Hi all!
My juvenile clownfish has been acting weird the last day or so and I'm concerned due to back to back recent losses in my tank and new additions.

Clownfish - since last night has been staying at the very top of the tank, on his side, above my thermometer. He swims around a bit if i kind of poke my finger in the water, but then just kinda stops and rides the bouancy back to the top to get back to the thermometer and just hangs out again. Thought it might've been an oxygen problem, let the filter push in some air and its been 5-10 min and he's just back up to the thermometer again.
He wouldn't be hosting such a tiny thermometer would he? My other clown is doing fine, just swimming in the rocks.

Concerns - within the last week I've had two fish deaths, both gobys. I decided to get a pistol/goby combo and the shrimp was fine but havent seen him since he was so tiny, but I lost the goby within a few hours and then found him the next day being feasted upon by my hermits. Fast forward to yesterday i get a diamond goby as a replacement and i mean within 20 minutes of adding him to the tank he was dead.

New additions - in the last week i added 4 corals. 3 of which seem to be doing fine: clove polyp, gsp, and a toadstool. The zoa I got with the first goby just doesnt seem to want to open fully, its been either fully closed or halfway open the whole time.

So any thoughts? Clownfish was just swimming with other clownfish for a minute and is now right back to the thermometer. They also have stopped coming to the top for food, they used to love coming up and saying hi :(

 

[Mr. Mojo Rising]

Can you post some pictures? And parameters? Also advise how old the tank is and the tank size. Do you have good surface agitation to keep the water oxygenated? The environment has a lot to do with how a fish acts so we need details on the tank itself. Thanks.

 

[Gumbies R Us]

Pictures or videos would greatly help. If you upload a video, make sure it is a youtube link

 

[Seafeather]

Sorry, they're not the clearest but he puts himself in a bad spot lol

He stays in this spot when he goes to the surface. He doesn't really go anywhere else like this. I moved the thermometer that was right there (to see if he was hosting it) but he didnt follow the thermometer.

Tank is a 20gal waterbox.
Temp is 78
Salinity is 1.026 (checked it this morning because it was a concern i had)
Parameters are all normal with my little test strips, though i will be taking in a sample later today when i return the previously mentioned dead goby. Maybe they will provide a more detailed report.
Surface agitation: there's a little but not much from the outtake of my filter. But I have a proper wavemaker coming in today that will help.
Tank is about 4ish months old.

As of about 20min ago he's back to relatively normal behavior (both clowns have discovered the small GSP i put in there yesterday and are investigating). I'm beginning to believe im just paranoid and my clowns are just weird

 

[James M]

Probably need more surface agitation, just off the picture alone it doesn’t look like you have any

 

[Seafeather]

Surface agitation will definitely be fixed soon. Wavemaker should be delivered within the next 3 hours. :)

A more comprehensive test on my water was done by an LFS and said it all looks perfect. So I'm thinking lack of O2 and him just being weird cause both clowns have moved to the bottom left of our tank and are having a blast.