r/ReefTank 2d ago

No judgment questions zone - July 20, 2026

3 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 4h ago

Coral Reef Long Presumed Dead Is Rediscovered 'Teeming with Life' Off Coast of Africa

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goodnewsnetwork.org
51 Upvotes

r/ReefTank 4h ago

July ‘26

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32 Upvotes

🪸🪸 CORAL 🪸🪸


r/ReefTank 1h ago

New clown found anemone in 2 days

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Upvotes

r/ReefTank 2h ago

Rare sighting of my Marine betta, B/W filters make it stand out the best.

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14 Upvotes

Captive Bred and have had her for almost a year at this point. She used to be so tiny.


r/ReefTank 21h ago

[Pic] Happy birthday to me!

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322 Upvotes

Came home to a dead yellow tang.

Showed no signs of distress. My wife said she heard splashing came in and yellow tang was swimming crazy and died. Not sure why or what happened. All other fish seem to be healthy no signs of distress. I'm sure the purple is happy to have the tank to himself now.


r/ReefTank 4h ago

[Pic] Do you like my aquarium? 🙂

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10 Upvotes

r/ReefTank 1h ago

Alveopora help

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Upvotes

Hello! New Alveopora owner here. Just received one yesterday- I thought it was looking pretty happy but noticed that two of the stalks were dark brown and shriveled- anyone know what could have cause this or what I can do? Sorry for image quality!


r/ReefTank 1h ago

[Pic] What’s everyone using to track their parameters?

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Upvotes

I’ve had a good experience using ReefTrak


r/ReefTank 1d ago

Three of my low tech, no-dosing soft coral reefs.

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199 Upvotes

r/ReefTank 14h ago

Looking for opinions.

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34 Upvotes

(Sorry for giant post, & Pump and power head off for the video)

This is my water box cube 20, it’s been in storage for 5 years after a fail on my first attempt. It’s been cleaned and completely redone with all new everything! Only thing I kept from first attempt was my rodi unit, Hanna salinity tester, light and power head, power head is an AI Nero 3, light is an Ai prime 16hd reef. Using Carib sea special grade arag-alive sand, and Carib sea LifeRock Nano Tree.

My cycle is done and I’m waiting for payday to add fish. I’ve kept a log book with every day from day 1 till now day 21. I know I want a ato unit asap, I’ve done every other day water top off since day 3, I’m really trying to do and learn everythingi can for this tank to be my little mixed reef tank I’ve dreamt of for so long.
((I had no idea what I was doing in 2021, I don’t even think the cycle was done when I added my first fish last time, it lived 8 days and I found it dead stuck to the back of the power head))

Question 1:
Eventually I want corals and a nem in the tank, mixed reef so think torches, hammers, zoas, acros, mushrooms, maybe bubble tip nem, wheat do you think the best placement for my power head is? The Nero 3 is awesome and can give 2000 gph flow rate, but I can’t mount it on the sides of the tank cause of kids will pull the outside magnet off lol, so where on that back glass would be best?

Question 2: what’s everyone’s favorite thermometer that’s not $100+ I’m on kinda a tight budget and need a better one then I have. The one on the side of the tank is NOT accurate, I borrowed a scientific thermometer to get a actual reading and my Hanna salinity meter is almost spot on, so that’s what I’ve been using, I’d like a temperature controller that will WiFi to my phone and tell me if there’s a problem. Using the 75W Eheim Jager heater btw, hope to upgrade to a TI one later.

last time I don’t think I cleaned or changed a filter sock one time, (I really didn’t know what I was doing) I’ve watched enough videos to know I don’t want to clean them, so today I ordered the NoSok filter floss cup thing to replace the socks, I think it will be nice but have any of y’all used them yet? I think they are new, but I’m sure that concept has been around for a while.

Finaly. What do you think about my rock scape, took me forever to decide how I wanted it to look, I like the tree idea, and the CaribSea kit made it really easy, I’m super happy with it, just want some other options. I have a couple little frag rocks that will be something, and a single rock in the back I hope to cover in zoas.

Let me know what you change or add or take away from my tank as of right now.


r/ReefTank 3h ago

[Pic] Green Star Polyps with Weird Tentacles

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4 Upvotes

I have some Green Star Polyps that I noticed the tips of two tentacles are split at the end. My assumption is this is similar to lizards regrowing two tails occasionally following losing their tail (so basically just damage that was regenerated a little funky), but I wanted to know if anyone else had seen this or had any insight.


r/ReefTank 5h ago

Should I pull the trigger on this deal?

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6 Upvotes

Currently in the process of cycling my first saltwater tank, I love it so far. I’m fascinated by all aspects of taking care of it and the possibilities of inhabitants. It’s only a 36 gallon and I already know I’m going to want a bigger one soon and I can get this 75 gallon tank new for only $127.


r/ReefTank 1h ago

Flow

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Upvotes

I think the flow is dialed in perfectly for this Willow toadstool. Every week it sheds and gets a little bigger. I can't wait until it takes up the entire center of this tank


r/ReefTank 21h ago

Judgemental A**

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79 Upvotes

I swear, all this fish does is post up, stare, and judge everyone, and everything…

Also, incredibly difficult to get good photos of. 🤣


r/ReefTank 14h ago

😊😊😊

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18 Upvotes

r/ReefTank 13h ago

Help ID’ing Hermit Crab

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15 Upvotes

Hi everyone,

I’ve got a hermit crab that’s currently about the size of a ping-pong ball. While I was initially inclined to call it a Dardanus megistos (those huge hermit crabs, just a juvenile), I’ve been struggling to actually find the right physical indicators that would indicate that.

Broadly speaking, it has green eyes on long stalks, red/white candy cane antennae, similarly-sized claws with the right being very slightly larger, and it having a sort of reddish brown coloration with some spots. It doesn’t have the deep red/maroon color you’d expect from even a juvenile megistos, and also lacks the blue knees that a few species of Dardanus have.

Any leads or hits? I’ve included some photos of it under white light.


r/ReefTank 1d ago

Haven't posted in awhile

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86 Upvotes

Tank is ~1.5 years old and has experienced a lot of changes, from lights, to wavemaker pumps, to livestock. The lights unfortunately bleached some corals until I made some moves. I had a large turbo snail that nearly wiped out all of my macroalgae in a week, which for those of you that recognize this tank, that snail nearly wiped out much of my natural filtration. For those unaware, this tank has no sump and no skimmer. Instead, I do a series of small water changes every day (6L/1.5g), and remove small clumps of macroalgae when necessary. There are two heaters (connected to a controller), two AI Orbit2 pumps, and a 700+gph canister filter that contains some rock rubble and is vastly infested with pineapple sponges that help filter. Currently, the only dosing I do is RedSea Magnesium because the RedSea salt I use runs low, sub 1200. There's also an air pump outside that has its tube running all the way inside that pumps a fresh stream of outside air.

Over the past year, the tank has gone through some unexpected outcomes, like a pack of bumblebee snails that ate 2 of my 3 clams in less than a week until I removed them. Fortunately, I was able to save my original crocea clam, though I wish I had read more about bumblebees and their supposed appetites. I've read that they're like peppermint shrimp, which can result in seemingly docile specimens that are actually a very similar looking species that'll hunt anything small enough... I too suffered that. I had 6 peppermints which ended up killing 2 small fish and an assorted amount of invertebrates and even corals.

I lost one chromis to jumping out, but still have the remaining 20 of the original 21. So far, they all still get along well, and some have even attempted breeding many times, but I've never seen surviving fry. I also removed a few rock pieces and moved some algaes and corals around, so the tank's look has changed. I introduced one small RTB Anemone over 6 months ago, and within a few months it started splitting. I now have SIX and will likely remove some over time.

The tank has been a wild ride, but it's still going strong.


r/ReefTank 1d ago

Snagged this rock from LFS. ID please

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64 Upvotes

Couple things.
—The black on the rock. It’s squishy. Maybe a sponge?
—This hitchhiker


r/ReefTank 6h ago

Innovative Marine Sump

2 Upvotes

Considering getting the IM EXT 100 or 150. Really love most things IM but I’ve been reading about how annoying it is that you can’t fit a filter roller in the sump. Ideally long term I would like a filter roller. I’ve considered just getting the stand, buying a Bashsea sump and plumbing everything myself but my inexperience in the plumbing aspect makes me nervous. Would it be worth it in the long run to just bite the bullet and take the extra time to plumb everything myself with a sump I will be fully pleased with? The ease of ordering the complete system is attractive though…


r/ReefTank 2h ago

Tracking water parameters

1 Upvotes

Hi all. I am just getting back into reef keeping after taking an 8 year break to finish college and find a job.
Back then I was logging parameters in a notebook and looking back I don’t really feel like I got anything from it. Mostly because I lacked consistency and flipping back and forth between pages to read numbers felt useless.
What is everyone using to track parameters, dosing, and other schedules you follow?


r/ReefTank 19h ago

[Pic] Rasta Zoa's P2, definitely one of my favorites

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21 Upvotes

This colony is really starting to take off.


r/ReefTank 7h ago

What are people using to measure their pH?

2 Upvotes

I know this sounds like a dumb question, but I can't find any mention of what systems people are using except the Hanna pH test kit. Are there any other recommendations?


r/ReefTank 4h ago

Innovative, marine 25 Lagoon problem

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1 Upvotes

Should I be concerned or would you believe it’s okay to still use? Tank is currently dry and open to others options for help thank you!


r/ReefTank 1d ago

Who will win this battle? I'll let ya know down the road 😁

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62 Upvotes

2 chalices competing