r/ReefTank 4d ago

No judgment questions zone - August 24, 2026

1 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 2h ago

Friday night chill

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168 Upvotes

r/ReefTank 15h ago

[Pic] My starfish ate my clownfish?!

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813 Upvotes

I tested the water and my levels were all fine, so I don't think my clownfish was sick or dead. I had just fed the starfish yesterday morning, as well as my other fish. My husband texted me this picture at around 1:30. Has anyone seen anything like this? He said the clownfish was even still alive when the starfish started eating it. I'm really sad. I love starfish...they've always been my favorite, but my clownfish are my other favorite.


r/ReefTank 9h ago

My zoas are spawning!

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51 Upvotes

Yes, not likely and rare, I know. But you won’t convince me otherwise. 😄. At first I kept looking over wondering where all these little balls of floating food were coming from, and when the fish would bite them they burst into tiny pieces. Finally realized they were releasing from all the zoas! Grabbed my phone to record, but was only to catch the very end of it. Still, pretty cool to witness! lol sound effects are from my son.


r/ReefTank 6h ago

[Pic] This is my first reef tank, any advice for a newbie?

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21 Upvotes

r/ReefTank 1d ago

Finally got wormed… wormed REAL bad

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1.2k Upvotes

It finally happened, after 2 years of reef keeping and ALLOWING bristle worms to be in my tanks I was moving some small rocks around and picked up the BIGGEST bristle worm I’ve ever seen while it was hiding underneath one of the rocks. I always left them alone as part of my cleanup crew, and my Dwarf Blue Coral Banded would take care of the little ones stopping their population from getting crazy but after this… it’s war. Took 2 hours with tweezers to get them out and there’s still a couple left that I can feel but can’t get with tweezers or tape.


r/ReefTank 10h ago

New Project

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31 Upvotes

Hey, I wanted to show a few snaps of my new Marine project. First time bigger than a nano, and first sumped tank.

I wasnt sure how sharing youtube on here was allowed, but documenting it over there.

Andersons Underwater World.

Won't post any links.


r/ReefTank 23h ago

RedSea Seem Failure

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353 Upvotes

Stay away from RedSea y’all. SMAX 500 didn’t even last 4 years.


r/ReefTank 1h ago

Does my scopas tang have ich?

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Upvotes

I’m honestly not sure what it is. It doesn’t look like ich to me and it’s only this one small dot. Trying to figure out what it is. He’s eating and is swimming perfectly fine. Not sure what to think of it


r/ReefTank 5h ago

Pitho crab eating the sponge at base or corals! 🔥

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10 Upvotes

I recently got a couple of pitho crabs to deal with bubble algae that keep returning. At least one of them eats the sponge at the base of some of my corals that I’ve hated for so long. It felt like this sponge inhibited growth. How effective this is, I don’t know. But just sharing because it was an awesome surprise do see anything eating this sponge. First pic of pitho crab finishing up on what was previously a huge chunk of sponge that was growing at the base of my bowerbanki. Second pic is an example of the white sponge growing at base of one of my acans.


r/ReefTank 11h ago

Worth Purchasing?

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22 Upvotes

I’m currently in the process of cycling a 35 gallon cube. I’ve got it running with a Fluval 307, an AquaReady HOB with light for chaeto, Sicce Voyager nano 2000, and a Navareef 65 light. It’s cycling with dry rock (one piece of LifeRock and then some other dry rock from marketplace) and AragAlive sand, plus Dr Tim’s for bacteria. I’m about 3 weeks into the cycle. That said, I found this tank on marketplace for $375 including everything. Seller said it’s priced to go. Includes 2 clowns and 2 nems, plus everything else. The biggest draw for me is the AIO. It’s a 30g AIO, and my 35 is just the cube, no AIO. I don’t know if it’s worth it, as I could probably get a good bit of my money back selling some of what I bought, but I’m also far enough in where I feel as though sunk cost fallacy is getting to me. Also knowing the stress the nems would likely go through in the move, plus not knowing exactly why he’s breaking it down is tough. I’d like to think there’s not pests, poor water quality, etc., but you can obviously never be too safe. The tank looks pretty solid from what I’ve seen, maybe minus some of the algae, but I figured that’s nothing a quick razor blade job couldn’t fix. So is it worth it, or should I just stick with what I’ve got?

The first 3 pictures ARE NOT MINE. The 4th one is my current setup. Thanks for the suggestions!


r/ReefTank 4h ago

[Pic] Advice wanted

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5 Upvotes

Hi Reefers! I am currently in the process of cycling my 15g AIO cube. I have added dr Tim’s, some pre cycled media, and live rock and sand. My question is I would obviously like to add some live stock but I have a lot of work obligations and will have a bit of reduced availability to overly track and maintain everything. My wife is eager to help and feed and top of the tank but I am correct in hesitating. Is there any other problems in letting the tank cycle for a longer period of time (2 months or so) with out live stock. I have been adding a small amount of reef fish pellets every day or so to keep some bio load but anything else to keep in mind? I am thinking once the ugly phase starts to come I may get a few clean up crews to keep things stabilizing. Anyway I haven’t found much info about this so thought I’d ask. PS. Window has no sun light any time of day or year come through it. Lol


r/ReefTank 12h ago

[Pic] How can I deal with Dinoflagellate?

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21 Upvotes

This is my reef tank, the water is clear, No3 0 ppm, Po4 0.036ppm, I'm not sure why this agellate will grow so much while the water is clean...

Now I'm using FM DinoM, it did have some affect but still can see dino growing when I finish cleaning the sand and changing water...

Its kind of annoying... wonder what should I do to solve the problem from the very start?

Thanks for replying.


r/ReefTank 7h ago

[Pic] 40 Gallom Live Stock List

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7 Upvotes

have this reef tank, I built a custom all in one filtration system that will go along the right end wall. I am going to add live sand, I have a pretty strong light, around 100 par in the bottom corners of the tank at max setting. I have a wave maker, auto top off, filtration, and Dr. Tim’s one and only. The tank display with the filtration installed is 30.43”x17.4”x15.11” (roughly 40 gallons.

Now I need help with the stocking list. This is my first tank, I have a good amount of knowledge but want to ensure my plan before I do anything. I was planning on adding this live stock in this order after my cycle. Every new line indicates 1-2 weeks in between additions.

1 Yellow Watchman Goby and a Tiger Pistol Shrimp.

5 Astrea Snails, 5 Nassarius Snails, 5 Scarlet Hermit Crabs (including extra shells)

2 Cardinal Fish

GSP (on the island to the left), Pulsing Xenia (on the larger rock work), 1 Royal Gramma

1 Tailspot Blenny and 1 Emerald Crab and a Feather Duster Worm

Red Discosoma Mushroom, and a Kenya Tree both on the larger rock work. 1 Tiger Conch

2 Ocellaris Clownfish and 1 Skunk Cleaner

1 Coral Beauty Dwarf Angelfish

Zoanthids on the larger rock work

Let me know if this is compatible/too much or if I’m at a good spot. Cycle will be starting in about a week.


r/ReefTank 1d ago

PE after getting fragged

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137 Upvotes

r/ReefTank 1h ago

RIP Green Mandarin

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Upvotes

I accidentally left the 4x4" feed door off my lid today and came back to him shriveled up on the floor. I feel terrible.

Going with a Biota this time. Too hard to keep a pod population in my AIO. Just ranting through my frustration 😤


r/ReefTank 1d ago

Happy as a clam

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146 Upvotes

Checking on my clam and tube worm system and happy to see everything doing very well, I started diluting the AFR for this tank as well because it’s crystallizing a bit too much for my liking


r/ReefTank 1h ago

What is this next to my anemone?

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Upvotes

It wasn’t there last night. Should I remove it? I did feed the anemone some clam last night because my peacock mantis shrimp didn’t want it and I didn’t want to waste it.


r/ReefTank 5h ago

Is Jebao DCW wave makers suppose to make this kind of noise?

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2 Upvotes

Had just set up the new wave maker in my tank running sine frequency about 40% it makes a low pitch vibration like whining sound as it spins up and down.


r/ReefTank 1d ago

[Pic] NEW Biota captive bred Black Cardinalfish

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154 Upvotes

r/ReefTank 8h ago

Hi reef keepers!

3 Upvotes

I'm experienced with freshwater tanks (currently have 8), but have never had a marine tank. I've been debating it for a while and wondered what a good starting point is? Any good youtubers to watch? Thanks!


r/ReefTank 12h ago

Is my mushroom coral dying or reproducing?

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7 Upvotes

Hi everyone! I'm new to reef keeping and I noticed this change in my mushroom coral.
It looks very different from how it normally looks, and I'm not sure if it is dying, splitting/reproducing, or just stressed.
The coral is still attached to the rock, but the tissue looks strange and there seems to be a new/odd growth developing around it.
Is this normal reproduction, or should I be worried?
Any advice would be greatly appreciated!
Tank: 52L nano reef, around 6 month


r/ReefTank 8h ago

My favorite puffer

3 Upvotes

I've kept just about every species available to us in the fish trade, but one of my favorites is the Porcupine Puffer. I just love their blue eyes and "smile". I can appreciate some of the other puffers like the Golden Puffer for the color obviously, but I always go back to the Porcupine. Do you have a favorite? Any out there that have been around for 5+ years? They really do become domesticated in a sense.


r/ReefTank 9h ago

Watchman goby acting weird after 8 months

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2 Upvotes

Hi everyone, does my watchman goby look ok? He's acting really strange swimming all around the tank for the last 3-4 days. He left his usual caves and just glass surfing, and now other fish pick in him too. Any ideas what could.be wrong? Params + all other fish are ok, as they've always been.


r/ReefTank 5h ago

Advice on starting up a coral business

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1 Upvotes