r/ReefTank • • 3d ago

No judgment questions zone - October 12, 2026

0 Upvotes

Here is the place to post questions about pest ID, coral/fish ID, your cycle, or any other questions that generally wouldn't start up a conversation. If you have an interesting or unique question please create a new thread so everyone can discuss it in length!

​

Pest ID guide

​

BRS pest guide

BRS beginner resources

BRS 52 weeks of reefing YouTube series


r/ReefTank • • 5h ago

[Pic] I think this may be the “holy grail” of Ricordea floridas

Post image
107 Upvotes

r/ReefTank • • 3h ago

My 20g nano reef

Thumbnail
gallery
31 Upvotes

r/ReefTank • • 1h ago

Good lord these little guys are gorgeous!! Just got two for my tank

Enable HLS to view with audio, or disable this notification

• Upvotes

r/ReefTank • • 3h ago

feeding time

Enable HLS to view with audio, or disable this notification

28 Upvotes

everyone loves when i dose phytofeast


r/ReefTank • • 12h ago

My colony

Enable HLS to view with audio, or disable this notification

73 Upvotes

r/ReefTank • • 11h ago

The mother of all RODI systems

Thumbnail
gallery
36 Upvotes

Work in progress 👀👀👀


r/ReefTank • • 2h ago

Good lord these little guys are gorgeous. Just got two of them for my tank

Enable HLS to view with audio, or disable this notification

5 Upvotes

r/ReefTank • • 4h ago

Dino ID?

Enable HLS to view with audio, or disable this notification

6 Upvotes

I have already posted in R2R but posting here too for reach because I’m pulling my hair out trying to id and deal with these suckers.

I’ve tried a three day blackout didn’t work.
I’ve tried running UV sterilizer for weeks. didnt work.
tried siphoning them out and removing them…. hasn’t worked.

There’s no bubbles in the display. It’s not really stringy. It’s hanging out on the sand bed and on the lower part of my rocks and it stays there pretty much 24/7 it doesn’t really go away.

Any ideas?

DISCLAIMER: I’m not complaining. I know this is part of the hobby. I’m still learning, as is everyone in the hobby, please don’t yell at me (I’m more fragile than a Red Sea seam)


r/ReefTank • • 4h ago

[Pic] Day n Night

Post image
7 Upvotes

r/ReefTank • • 9h ago

[Pic] I like Zoas

Post image
13 Upvotes

So hard to get a good photo and of course half of them started closing when I switched the lights to get a picture.

11 varieties of Zoa/Paly in this tank alone. I think I have 14 between all my tanks but this one became the dedicated Zoa garden.


r/ReefTank • • 19h ago

Nothing like rearranging your rocks after cleaning when...

Thumbnail
gallery
96 Upvotes

crack. damned it I love this tank... going to the pet store to buy a temp before it let's go and floods my house...


r/ReefTank • • 13h ago

Anyone got experience with clowns+goniopora?

Enable HLS to view with audio, or disable this notification

27 Upvotes

gonio is around 2 months in my tank and the clowns are 6 days in.

usually after lights out (this is ambience light from the living room) the gonio did not retracted as bald as this but today after work i found them rubbing and wiggling really close onto the gonio ball.

do they eventually will kill my gonio? anyone have experience?


r/ReefTank • • 10h ago

My first reef tank

Thumbnail
gallery
13 Upvotes

Just filled my first nano tank and I’m so happy to start cycling, water is still a bit cloudy and I’m not sure about the water level in the display/sump but yay at least I started


r/ReefTank • • 10m ago

[Pic] Clownfish sick?

Post image
• Upvotes

Hi everyone, background into first:
New to the hobby, have a 25 gallon tank- started the bacteria cycle September 9th and midway last week I was getting reliable 0 ppm readings for ammonia so I figured it was time to get fish. The only other tool I’ve got is a refractometer and the salinity is 1.026.

I got a pair of onyx clownfish and did a drip acclimation for about an hour and introduced them to the tank. Didn’t quarantine them (stupidly) because I have no other fish. The first day they were pretty active but stayed away from the rock work. I tried feeding them but I read they usually refuse food when they get moved to a new tank so I didn’t think much of it.

Over the next couple days I noticed one of the clownfish seemed like its gills were pulsing a lot more and they no longer stayed together as a pair in the tank. The affected one was sitting in the sand inbetween short bouts of swimming. Around this time I added a snail and a hermit crab to the tank.

Went back to my local store a few times thinking something was wrong with my water and I brought a sample to get tested and all the other parameters are ok. Literally as I got home from that trip I checked on the fish and noticed white stringy poop hanging on it and similar white stringy things around its gills. So I immediately thought parasites and did a 30% water change and dosed some prazi. Also this whole time both fish were still ignoring food (which I did my best to scoop up so that it wouldn’t rot).

Most of that evening the affected clownfish was popping up to the surface and swimming erratically. And then it died :( I fished it out and tried my best to look over its body and gills but whatever white stringy bits I saw before weren’t there anymore.

So now my attention is on making sure the second one doesn’t die 😭. It’s been hanging out near the sandbed and this morning I noticed there was that pretty big white spot on its side which you can see in the picture. It doesn’t seem to be gasping or anything like the other one was but I do feel like its color is a bit paler than it first was.

Any input would be appreciated


r/ReefTank • • 4h ago

Fresh Frags

Thumbnail
gallery
4 Upvotes

It’s been a fragging kind of week for us to list on our site and make room in our main displays.

Have been spending some time growing out and organizing some colorful frags lately, and I’m loving how these are turning out! 🪸💚💜 Always fun seeing what pops under the reef lights.

I guess you could say I’m just goni with the flow while my Acro obsession keeps branching out! 🤣

What are everyone’s personal favorites in the reef tank world? Are you team Acro, Goni, zoas, euphyllia, mushrooms, or something totally different? Always love seeing what everyone else is obsessed with! 🐠


r/ReefTank • • 8h ago

DIY stand update

Thumbnail
gallery
6 Upvotes

Thoughts on my attempt at a diy stand for my tank plus sump? Still haven’t sanded or painted. Took me WAY longer than I expected 😭


r/ReefTank • • 23h ago

Researchers find that putting a healthy coral against a bleached one heals the bleached one

Thumbnail science.org
86 Upvotes

The study was on Pocillopora damicornis, a bleached coral put against a healthy one for 4 days healed within weeks. The test was on frags from the same colony.


r/ReefTank • • 8h ago

What are these little Fellas

Thumbnail
gallery
4 Upvotes

Got this frag the other day and noticed what I had thought was algea on the frag. Did my usual dip and crap of crud off the frag and though I got these little things. Low and behold... theyve popped out of hiding again and it kinda looks like there's more. They look like little feather duster worms to me but id love to hear thoughts.

Nervous I've introduced a pest from a ineffective dip.

Edit: thanks for the quick responses. Consensus was hydriods so I pulled the frag out and scraped and rinsed it off in another bucket. Cheers.


r/ReefTank • • 5h ago

Zoa relocation mystery

2 Upvotes

I came home after a long weekend and noticed about 25% of a small patch of zoas was gone (maybe 10 polyps).

There was a scheduled electrical works for one of the days i was away for 4-6 hours, i'd just assumed it was an adverse reaction (tank is 20g) to that and they'd melted.

Later this week i noticed a the polyps have turned up wedged into a crevice on the other side of the tank. They're tucked in between a large rock and a smaller rock with a devils hand. Still getting light and were open.

Any insight how this would happen? My CUC is 7 trochus and a hermit crab. Would a trochus have bulldozed through, somehow they've attached and then subsequently detached?

Or alternatively a trochus detaches them and they're them picked up by the flow and randomly deposited?

Cheers


r/ReefTank • • 1d ago

Happy 1/2 birthday to my first reef tank!

Thumbnail
gallery
103 Upvotes

Started on 4/12/26, I’ve had a relatively smooth start with only a few coral deaths and quickly have over crowded my reef.

Thanks to all this helpful info on reddit, my reefing buddy ChatGPT and YouTube I’ve been able to learn enough to keep this thing going.

Excited to see what the next 6 months bring!


r/ReefTank • • 1d ago

i just love my tank. it brings me so much joy.

Enable HLS to view with audio, or disable this notification

209 Upvotes

i know it’s not the most well designed or a big tank. but the joy of having it, maintaining it,seeing the fish and corals grow and just sitting and looking at it. it just makes me happy.

my biggest lesson from fish keeping is it’s not the fish you need to worry about, it’s the water. make sure the water is good and the fish and corals thrive.

just like our lives, all you need to worry about is the environment we’re in.


r/ReefTank • • 2h ago

Lawnmower Blenny Aggression

0 Upvotes

Hey all, I just added an orange spotted blenny to my already established tank made up of two clownfish and a lawnmower blenny. I noticed that my lawnmower blenny started attacking the new fish and now I’m thinking that he’s why my firefish goby died. Any suggestions?


r/ReefTank • • 11h ago

Mushroom ID please

Thumbnail
gallery
3 Upvotes

I cant get a straight answer on Google. I have since moved my tank around and there is a large one almost touching my frogspawn. Im not sure if I should remove it or move the spawn


r/ReefTank • • 4h ago

Stocking reccomendations?

0 Upvotes

Hey guys! I have a 15 gallon saltwater cube and im wanting to put a pair of clownfish in there. Is it possible to also put a Royal Gramma in there?