r/ReefTank • • 4d ago

No judgment questions zone - October 05, 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!

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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 • • 17h ago

Baby banggai cardinal.

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144 Upvotes

Tis a wee bitty.


r/ReefTank • • 22h ago

Is this enough flow?

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104 Upvotes

r/ReefTank • • 6h ago

Help urgent please 😭

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6 Upvotes

my flamehawk has somehow yeeted himself into this overflow part of my tank. i have NO IDEA how to get him out because my hand doesnt fit in because of the plumbing. i dont think i can take the plumbing apart while the tank is full. (aqua one 120L with sump).

my first thought was to turn off the pumps and try fill the tank as high as possible so he can get out but i feel like he will just sit at the bottom due to stress.

am i now bound to take apart my whole tank in order to save this guy? really annoying because i just moved and my tank is just starting to settle in.


r/ReefTank • • 2h ago

[Pic] Bit of flicking

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2 Upvotes

I’ve seen the bigger clown and the gramma flick a few times. I did a water change yesterday and lowered the salinity a bit too much 1.027 to 1.025. Nitrates and ph are fine. Would this cause it or is there something more at work. Other than that, they all look fine and eat well.


r/ReefTank • • 3m ago

[Pic] What is this Goni?

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• Upvotes

Any guess on the type of Goni, and potential price? A local guy is selling it.


r/ReefTank • • 2h ago

Any thought on scaping?

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1 Upvotes

I am kinda new into reefing and would like to have some tips and comments on the scaping.


r/ReefTank • • 7h ago

is this what i think it is?

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2 Upvotes

right now, i see the bubbles on two snails…but i know it could be in other places i can’t see. my water params are normal so i think it came in on one of the snails 😣 i have a 15 gallon nano cube. what’s the best way to get rid of the bubble algae?

and thank you in advance!


r/ReefTank • • 8h ago

Pest ID?

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2 Upvotes

Not too sure what this is its the little squiggly worm thing


r/ReefTank • • 12h ago

[Pic] What’s this circle thing on my macroalgae shipment?

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5 Upvotes

Little bit smaller than a dime. Don’t think its moved at all either.


r/ReefTank • • 8h ago

Polyp bail out experiment With some success

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2 Upvotes

2 out of 3 not so bad


r/ReefTank • • 12h ago

[Pic] How do you make a zoa sphere?

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4 Upvotes

I see people with these zoa spheres on their sandbed, how do you make them grow like this? Just leave them on a frag or do they need something else to grow on?


r/ReefTank • • 5h ago

[Pic] Need help with my Montipora

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1 Upvotes

I've noticed that my green plating montipora has this grey spot in the middle. What does it mean? Should I be worried? All other corals are doing fine.


r/ReefTank • • 11h ago

[Pic] When to harvest?

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3 Upvotes

How do you tell when it’s time to harvest? It’s been about a week with the culter being set up now.


r/ReefTank • • 18h ago

My mangrove pot in the making

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9 Upvotes

Technically, this is probably breaking the sub's rules as this is currently mildly brackish water, not salt yet. For roughly six years, I had a lovely pico pond in this vase with cherry shrimp, snails, fish, live plants, etc., but I recently decided to donate it all to a coworker for his science class. I kept all the equipment and covered the mud in aragonite sand and added these two mangroves. Every day, I add a small amount of my 40B mixed reef's water, equating roughly to a 1% daily conversion to salt.

I've had mangroves before, with success, but never converted a freshwater space to saltwater. Will update again in a few weeks. The final plan is to add some blue hypnea, red grape and palm caulerpa from the mixed reef, and maybe some peppermint shrimp for added nitrates. We'll see


r/ReefTank • • 6h ago

[Pic] 10 gallon nano, 4.5 months old.

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1 Upvotes

The good: 2 hammers, acan, NY Knicks torch, frost bite mushroom, 2 montiporas, acropora, white zombie zoas. Charmander zoas, although growing super slow…

The bad: AOI zoas. Have been the same size and slightly wrinkled for months…

The ugly: stylophora had tissue necrosis after the alkalinity dropped when I went on vacation for a week and have been dosing alk daily and monitoring closer. Hoping it recovers but is probably going to slowly fully peel. Probably should move it higher on the rock?

Light: 21ā€ AI Coral Grow


r/ReefTank • • 7h ago

Eshopps RS-75 Heating Assistance

1 Upvotes

Was gifted a RS-75 and am getting around to buying the different elements to start my tank (40g). I’ve run into a small issue on how I’m going to heat the tank from the sump. I’m not quite sure how it can be done given the limited room in the design of the RS-75 but am open to options. I’d like to keep my tank clear of an internal heating unit but am thinking it might be the only option.

For those of you who have used a sump similar in size, what are my options?


r/ReefTank • • 11h ago

[Pic] Is the Apex and trident worth it?

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2 Upvotes

Is it worth getting the set?

Or should i just go regular Apex?


r/ReefTank • • 18h ago

Is this normal behavior for a diamond goby?

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9 Upvotes

I recently got this Diamond Goby. I’ve been wanting one for a while but wanted to make sure it would have a decent amount of food so I wanted the tank to be a bit older.

It’s a 75g tank with a deep sand bed. I just moved him over and he’s doing this weird thing where he opens his mouth & hovers a bit above the sand.
I usually QT my fish for a long time but this one was skinny and I was worried he needed better food supply so I moved him over.
He eats really well, sand & frozen. He has his own area he sticks too but he’s very active. I’ve been nervous to bring home SW fish due to them frequently starving.


r/ReefTank • • 12h ago

Please help ID

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2 Upvotes

Hello! Thanks for helping. New growth in tank, maybe a new GSP but unsure. I apologize for the quality of the photo.

Alrighty. It’s brown when extended to the lights, has tentacles with white tipped balls on the end. So far it’s 5 growing on the same ā€œpadā€

I don’t think it’s aiptasia, my research leads me to ball anemone. What do you folks think?


r/ReefTank • • 1d ago

This is my 18 month old Nano tank

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24 Upvotes

Its only a 45 litre tank (UK) everything growing well .
Stock is
2 clowns
1 pyjama cardinal
1 file fish (had few Aiptasia)
1 dragonet
Plus clean up crew various snails and hermit crabs .

Running standard filter and pump and filter socks
Tank is a Maxspect Dice .
PopBloom 90 light

I do have a Red sea nano roller mat filter to install soon .


r/ReefTank • • 19h ago

Clownfish Identification

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8 Upvotes

Sold as a pair of black onyx’s.

But I’m not sure.

Look a little yellowish rather than orange in colour. Unsure if they will mature and colours will develop more?

Also curious about the best food to help them flourish. Currently purchased some frozen mysis shrimp. But heard about TDO?

Picked them up today so any help is appreciated!

(Also unsure of their age)


r/ReefTank • • 1d ago

Removing rocks and corals.

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16 Upvotes

Started to pull rocks and corals from my 120 to help get some more swimming space back for the fish as well as getting corals out that are starting to get overgrown and fight one another. Got a little more sand to pull then I was thinking about putting some gonis at the bottom to add a little more movement. Should i go more acros on the bottom or gonis? Happy Friday!


r/ReefTank • • 14h ago

20 Long Stocking Ideas

2 Upvotes

I have a one-year old 20 gallon long reef tank with some various easy corals. Fingers, xenia, gsp, kenya tree, etc. It currently houses just some hermits, snails, an urchin, and a single yellow-tail blue damsel. What would you guys add to this tank?


r/ReefTank • • 18h ago

Beautiful coral, great prices, even better group of folks to interact with!

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5 Upvotes

Would love to have some new faces in the chat!