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!

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Pest ID guide

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BRS pest guide

BRS beginner resources

BRS 52 weeks of reefing YouTube series


r/ReefTank • • 1h ago

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

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• Upvotes

r/ReefTank • • 8h ago

My colony

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70 Upvotes

r/ReefTank • • 7h ago

The mother of all RODI systems

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31 Upvotes

Work in progress 👀👀👀


r/ReefTank • • 16h ago

Nothing like rearranging your rocks after cleaning when...

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88 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 • • 6h ago

My first reef tank

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14 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 • • 9h ago

Anyone got experience with clowns+goniopora?

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23 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 • • 25m ago

Dino ID?

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• 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 • • 30m ago

[Pic] Day n Night

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• Upvotes

r/ReefTank • • 5h ago

[Pic] I like Zoas

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7 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 • • 4h ago

DIY stand update

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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 • • 19h ago

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

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82 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 • • 4h ago

What are these little Fellas

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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 • • 1h ago

Zoa relocation mystery

• 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 • • 23h ago

Happy 1/2 birthday to my first reef tank!

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102 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.

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204 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 • • 3m ago

feeding time

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• Upvotes

everyone loves when i dose phytofeast


r/ReefTank • • 7h ago

Mushroom ID please

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4 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 • • 26m ago

Fresh Frags

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• 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 • • 1h ago

Stocking reccomendations?

• 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?


r/ReefTank • • 1h ago

What’s wrong with my purple tang? What spot above the red line

• Upvotes

I just noticed this white spot on my purple tang. Possibly 4years old. I bought a fauna Marin icp
Test and plan to send it out Monday after my weekly maintenance. Anyone know what’s going on? Pic in the first comment


r/ReefTank • • 21h ago

[Pic] Bryopsis

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33 Upvotes

Dosed Reef Flux, how long before I notice the algae turning grey? The picture doesn't show much.. but mainly on the upper rockwork around the SPS.

It has been a week and no changes, is it safe to dose more?


r/ReefTank • • 2h ago

nano reef cycle question

1 Upvotes

So I have about 10 years of experience in the hobby but that was also almost 10 years ago. I recently wanted to dip my toe back in the water and get started on a nice little nano reef. Found a steal of a setup on market place (innovative marine 10gal, ai prime light, ATO and DIY hood) and went to my lfs to get the rest. I was talking with one of the employees about how the indistry has changed and he seemed pretty well experienced. Live aquaria is apparently trash now, live rock is much less available and instead carib sea "life rock" is the standard, and the most shocking piece of advise i was given was how to cycle my tank. Now ive cycled quite a few tanks before and was planning on doing some "life rock", live sand, ammonia, and an api test kit and wait like normal. He said the best way is to simply add the rock and sand and throw a fish in there and even a hardy coral and do a fish in cycle day 1. "Just let the sand settle". didnt even recommend getting a test kit. Online seems to refute these claims saying a fish in cycle is risky and harmful to the fish. Before I go any farther I was looking for the internets take on things. I didnt end up getting a fish or coral (yet) and havent dosed ammonia (yet). still deciding what path I want to do. Any bonus info on how the industry has changed is appreciated in here as well. Thanks!


r/ReefTank • • 3h ago

What is on my Zoa colony?

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0 Upvotes

What is growing under and through my zoa colony? AI suggested a nudibranch, but it does not look like pictures I've seen. Whatever it is, it is pushing little pieces out in several places. Should I dip it? I've had this colony four months and don't want to lose it!


r/ReefTank • • 3h ago

[Pic] With how large the anemone is, you'd think she'd share

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0 Upvotes

She's a menace. Makes him stay below it all the time.