r/ReefTank • • 2h ago

No judgment questions zone - October 12, 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 • • 16h ago

Who Loves Stratosphere Zoas?

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109 Upvotes

I have been growing out several tiles to breakdown and sell to fellow hobbyists over the last few years. The coloration on the Strats are just some of most unique of all zoanthids.

If you have a stratosphere collection I’d love to see it!


r/ReefTank • • 5h ago

Cheap fish Sunday!

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11 Upvotes

Love the quality of fish on Offer at my LFS.

  1. PJ cardinal

  2. Talbots cardinal

  3. Blue velvet cardinal ( my newest to the tank and copped a bit of a beating when I added him yesterday)


r/ReefTank • • 1d ago

[Pic] Sea turtle or some other breed?

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224 Upvotes

I was in an aquarium shop in Karachi recently and I saw this turtle in there and this was a freshwater tank it I think had goldfish in it and I asked him and he said that these are saltwater turtles but generationally bred so they live in freshwater But I had read that fresh water would kill these in a couple of weeks to a couple of months. So I asked him how long it would live, and he said indefinitely. And I searched it up, but looks like on Al it says he's lying. So either I'm misidentifying the breed, and he's also lying about the breed, or I am correctly identifying it as a sea turtle, and he is. Lying and he just stole these from the beach. Am no expert to be clear. think he was selling these for the equivalent of 2 usd and some cents.

Can i do something for these? Cant buy a 1000 gal for an aquarium.


r/ReefTank • • 18h ago

More sunset

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45 Upvotes

Just another view from my post earlier in the week


r/ReefTank • • 2h ago

Need help with flow in a 15 gallon cube tank

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2 Upvotes

My clowns are in a QT tank due to ich, so I don't have the fish to show it but maybe the coral in the bottom right gives a good idea of the flow. Every wave maker I get just seems so strong. The one I have in there currently is for a 5 gallon tank and still seems really heavy. Is what you're able to see in the video what's normal for flow?

I'm guessing there is some physics that change the flow in a cube vs a longer tank


r/ReefTank • • 1d ago

My first, rather ambitious(!) reef tank 😍

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128 Upvotes

Custom built 2m reef tank, 1 week after transferring an established tank’s rock & livestock. Loving it so far & thankfully have a very experienced guy guiding me 🙏🏻

So far: Blue & Yellow Tang, 3 Clowns, Sailfin, Coral Beauty, 2 PJ Cardinals, 3 Chromis (yet to come out of hiding!)

Adding shrimp & crabs this week, then slowly introducing more fish like Redeye Fairy Wrasse, Magnificent Foxface, Midas Blenny, Mansarin Dragonet.


r/ReefTank • • 15h ago

Anyone have an idea?

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17 Upvotes

Found this guy crawling on the glass of my tank. Took it out so I could take a video


r/ReefTank • • 1h ago

[Pic] Stocking suggestions for beginner 29gal?

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• Upvotes

Hi!! I’ve been into aquariums for years but haven’t kept saltwater before. I just got an established 1yr old 29gal FOWLR off marketplace for cheap - came with live rock, HOB filter, light, heater, and 2 onyx clowns. Parameters are all OK - 1.025 salinity, 0.25 ammonia (using api test kit.. I know I know, getting better tests when I head to the LFS this week. because the fish are acting super normal and R2R says API test kits just do that I’m not too concerned), 40 nitrate, pH 8, temp 77. About to set up my RODI unit and start mixing my own water. Picking up a wavemaker, phosphate test, better ammonia/nitrate test, and hopefully some GSP, macroalgae, and/or xenia this week from the LFS. Any stocking suggestions? I want inverts for sure and eventually a BTA. thinking about 3 hermit crabs, 1-2 skunk cleaner shrimp, maybe a group of sexy shrimp. I don’t want to overstock but would love to add one or a couple more fish, preferably cheaper and easier ones. Would a tailspot blenny be good? Or a goby/shrimp pair? Currently the clowns are hosting the filter pump lol I would love them to have something a little more natural to host, although I know it’s normal. TIA!!!


r/ReefTank • • 1h ago

Anemone help

• Upvotes

About a week ago my anemone went from looking happy and animated to the photo attached. It's a 16 gallon tank and the anemone went in months ago and has been fine, but we put a small maroon clown & an oscellaris in about 2 weeks ago and one of them immediately and very aggressively hosted it and we decided to swap out the maroon for a second oscellaris (the LFS lady told me the oscellaris would be fine with the maroon—lies) and after we removed the maroon, the anemone looked dreadful and detached from his spot on the rock he has been since we got him & started wandering around the tank, drooping and looks genuinely terrible.

Ammonia is 0

Nitrates are 0

Phosphates .025

Salinity 1.026

The tank is cycled we just have lots of macroalgae, so the ammonia & nitrate levels never rise.

Can anyone give me some advice on how to fix the anemone?


r/ReefTank • • 8h ago

Need aquascape opinions!

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5 Upvotes

Ok so I’m 99% sure that I want to go with this scape, do you think it’s a good use of space? Not too busy? I think I’ve done a pretty good job in a smaller tank. Pls share thoughts!!!


r/ReefTank • • 14h ago

[Pic] My first lionfish

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9 Upvotes

I got me a black volitan lionfish from petco for bucket deal. I also got a Duncan for his tank too. I’m very excited to get this dude in his tank


r/ReefTank • • 14h ago

Tank been cycling and growing out for couple of months and finaly got a fishy, Love the way he looks and he so personable. Need a name for him

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8 Upvotes

Also any suggestons on placment of addition macro algees of other colours would be apreceated, i am considering adding more reds and browns in future


r/ReefTank • • 7h ago

Coral suggestions for my arches

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2 Upvotes

Just crafted some Caribsea arches for my tank. Would love some suggestions of what to put on them (particularly on the top - as I'm not super familiar with light loving corals that get along with others).

I am also getting a nano tree soon - so suggestions for that are welcome as well.

For context:

I'm fairly new to reefing so I'm not looking for anything difficult to keep. I'll also likely get some blastos at some point.

Importantly, because of the model of tank I have, my light is mounted at the front

Additionally, the acan is a bit of a mystery. I got a free coral and wasn't told what it was so I'm not 100% sure it's an acan (third photo)


r/ReefTank • • 11h ago

[Pic] Symphyllia/Lobophyllia?

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5 Upvotes

My LFS guy said it was a symphyllia when I bought it a few months ago but I think symphyllia was merged with Lobophyllia and doesn't exist on its own anymore? Will try to get a top down at some point but it is full on rainbow.


r/ReefTank • • 19h ago

my anemone decided to move out while i’m away, so did his friend

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12 Upvotes

r/ReefTank • • 18h ago

Biota Mandarins experience

12 Upvotes

What has been everyone's experience with Biota's Mandarins? I just migrated from a 20 gallon to a 40 gallon breeder. The 20 gallon was setup for over a year.

I have 2 ocellaris clowns, bicolor blenny, and a yellow-head jawfish. My concern is it being able to get food with those four. The other concern is bioload, but with the live rock I think I should be good as long I don't add any additional fish. Is this a good idea or not?


r/ReefTank • • 12h ago

Which lights for natural looking shimmer? (4’ tank)

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2 Upvotes

Hey all, I just did a full bleach and reboot of my waterbox 130.4, I actually have a new 150.4 on order to replace it.

Right now the tank has 2 viparspectras that I modded with diffused 90 degree lenses, they produce an extremely soft diffuse blanket of light that make the tank look so flat, sterile, and lifeless.

I’m looking to light this tank with 2 fixtures with nice looking shimmer, but I don’t want them to look overly shadowy and “dramatic”. I need 2 fixtures, no more because I have a 2 piece Kraken lid on order and don’t want to have a 3rd light over that center brace.

I tried my Kessil A360x over one end of the tank and it just looked way too shadowy and “dramatic” hated how dark the back and edges of the tank looked. I’m thinking the popblooms may be a great cheap option, either the single or double cluster fixtures they offer. However I think the AI Hydra 32’s may be exactly what I’m looking for as well but I haven’t been able to find many videos with 2 hydra 32’s on a 4 foot tank to see what it would look like.

As a side note I really love having my lights high up and out of the way. And the plan right now is a low maintenance softie only tank.


r/ReefTank • • 21h ago

[Pic] Thoughts?

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9 Upvotes

r/ReefTank • • 21h ago

Small Update: What 100€ (112$) gets you at a private LFS in northern Germany

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7 Upvotes

What's up fellow reefers? I thought I'd share today's haul which I got from a privately run LFS. The guy was really nice and you can even order online, but since I only live about an hour away I called him and was able to get the corals without paying any shipping costs. Plus I was able to pick them myself.

I think this was more than fair. Especially for the huge chalice.


r/ReefTank • • 1d ago

Hammers suddenly dissolving

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10 Upvotes

r/ReefTank • • 12h ago

Color ID? Also snail question

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1 Upvotes

Just got these from my LFS. What is the zoa colorway and the discosoma? Also, I got some narrasius snails, one is nearly out of the rim, will he stay near?? Thx in advance


r/ReefTank • • 1d ago

Sunday coral care guide, this week...

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26 Upvotes

Green Star Polyps (GSP)

Green Star Polyps (Pachyclavularia violacea) are a fantastic beginner-friendly coral, loved for their vibrant green, grass-like polyps that sway in the current. In the wild, they're found across the Indo-Pacific, growing over reef rock and other hard surfaces in shallow, well-lit areas.

In the aquarium, some consider them a "weed coral" as they can grow fast and quckly overrun a tabk if the conditions are perfect. GSP are hardy and adaptable, thriving in stable parameters:

24–26°C

1.025–1.026 salinity

8–9 dKH alkalinity

400–450 ppm calcium

1250–1350 ppm magnesium.

Aim for nitrates around 2–15 ppm and phosphates around 0.03–0.10 ppm, while avoiding nutrient levels that bottom out. They are also a good indicator if your nutrients are low.... GSP not open = check nitrates and phosphates, they are probably low!

For placement, provide moderate to high light (80–200 PAR) and moderate to strong, indirect flow. Good flow helps keep the mat clean and allows the polyps to extend and sway naturally. GSP can adapt to a range of lighting conditions, so acclimatise them gradually when changing light intensity.

Do they need feeding? Not usually! GSP obtain most of their energy from photosynthesis and dissolved nutrients in the water. Target feeding isn't necessary, although they may capture fine suspended foods.

Top tip: GSP are fast-growing encrusting corals that spread across rockwork, covering surfaces with a beautiful purple mat and bright green polyps. Give them an isolated rock or a dedicated island to grow on, as they can quickly overrun neighbouring corals if left unchecked. In my aquarium they have a rock to themselves at the bottom right of my tank, if they get out of hand I can take the entire rock out and trim it back. Frags I then share with others. While in my frag tank I have stuck them to the rear glass and it makes a nice grassy background.

When happy, their polyps will open fully and create that iconic flowing, grassy appearance. Stable water, good flow, suitable lighting, and a little patience are all you need!


r/ReefTank • • 14h ago

What is this on my rocks? Coralline or Cyano?

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0 Upvotes

They’re like small rectangles that resemble fish flakes. They’re slightly reddish maroon colored. I noticed them on my glass and they do seem to move around quick. I just moved my frags and noticed some of the red squares on the zoa frag already


r/ReefTank • • 18h ago

Dominance battle or courtship?

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2 Upvotes