r/aquarium • u/ThatJester123 • 2h ago
Help Cyano?
Could anybody confirm if this is some kind of Cyanobacteria? I stared being scared of anything since one issue in my life… Am I in danger or anything? Its been in my tank for 4 months.
r/aquarium • u/inkisbad124 • 18d ago
We're giving the subreddit a fresh new look, and we'd love for the community to help!
Starting now through July 10, 2026 11pm (GMT-7), we're accepting submissions for a new r/aquarium banner.
Rules
• Your submission must be your *own original photo.*
• The photo should be aquarium-related (freshwater, saltwater, aquascapes, planted tanks, shrimp, fish, invertebrates, etc.).
• Photos should be in a horizontal (landscape) orientation, as Reddit banner images are wide and short. Horizontal photos are much more likely to fit the required banner dimensions without excessive cropping.
• High-resolution images are strongly preferred.
• No watermarks, text, logos, or AI-generated images.
How to Enter
Post your image as a comment below. If Reddit compresses the image too much, you may also include a link to a full-resolution version.
You may submit more than one photo, but please keep it to a reasonable number.
How the Winner Will Be Chosen
Submissions will close on July 10, 2026 (GMT-7). After that, the moderation team will review all eligible entries and select the image that best represents the community while also working well within Reddit's banner dimensions.
By submitting an image, you grant the r/aquarium moderation team permission to use it as the subreddit banner. You retain ownership of your photo and may withdraw permission at any time by contacting the moderation team.
We can't wait to see your amazing aquariums. Thank you for helping shape the look of r/aquarium, and good luck!
r/aquarium • u/inkisbad124 • Jun 10 '26
Hey everyone,
We heard your feedback loud and clear regarding the recent icon change. The goal is always to keep r/aquarium a vibrant, welcoming space that reflects the incredible passion of our hobbyists, and it’s clear the community prefers authentic, human-made artwork to represent us.
An incredibly talented artist in our community, u/SuicidalFlame (Check out their tumblr too! https://firenagy.tumblr.com), generously stepped up and designed a brand-new, custom icon for the subreddit! We are absolutely thrilled to debut their work today. Please join us in giving them a massive thank you in the comments below for dedicating their time and talent to leveling up our community's look!
While we always welcome constructive feedback and open discussion about the state of the subreddit, the mod team has a zero-tolerance policy for harassment.
Lately, targeted mass-reporting and personal harassment have been directed at our moderators. We want to be entirely transparent: if you are unhappy with the management of this subreddit or feel the need to harass the people who volunteer to keep it running, you are more than welcome to leave.
Healthy debate is fine; stalking, toxicity, and abusing the report button are not. Future instances of targeted harassment will result in an immediate permanent ban from the community and will be escalated directly to Reddit Admin for violating the site-wide Content Policy against harassment.
Thank you to the 99% of you who make this a wonderful, supportive place to share our tanks every single day. Enjoy the beautiful new look!
r/aquarium • u/ThatJester123 • 2h ago
Could anybody confirm if this is some kind of Cyanobacteria? I stared being scared of anything since one issue in my life… Am I in danger or anything? Its been in my tank for 4 months.
r/aquarium • u/BoysenberryTime2777 • 16h ago
Pls help!! I feel so bad just throwing it away
r/aquarium • u/The_Doge_Coin • 3h ago
This is my first aquarium, so I’m sorry in advance for some mistakes. It’s a four week old walstad tank, and some of my plants are growing with very little leaves, yellowing and pale, almost translucent leaves.
Any help identifying the problem would be amazing.
r/aquarium • u/ItsB_06 • 5h ago
Hi everyone.
I just set up my 200l tank a few days ago.
I’m using a canister filter from tetra, the tetra ex1000.
I accidentally moved the outlet and therefore a bit of water splashed out.
I didn’t realize water was dripping down the back glass because I was hurrying to get some towels.
Now there’s an area on the mat beneath the tank, which I assume became wet.
Is it bad?
I hope it’s visible on the picture.
I’m already so scared that it’s leaking or something cus it’s a rimless tank.
Thanks in advance!
r/aquarium • u/Cuyigan • 7m ago
Came back after being away a month there was a huge growth spurt. I think I'm going to start attaching it to the walls or letting it hang over.
r/aquarium • u/Independent_Tie_383 • 8m ago
I’m quite new to fish keeping, it all started when my fiancé bought home a “depressed” looking goldfish while she was out getting food for our doggos
Now 3 months later, I’ve purchased a 120L tank from Facebook marketplace, and spent hours lurking aquarium subreddits looking on for ideas and honestly just watching the tank
Currently on the day 5 since our brand new second hand tank was filled and wanted to know how my parameters look, all 3 filters came from cycled tanks, and can anybody recommend some more plants for the tank? My substrate is washed Sydney river sand and some natural stones from pet barn, and any liquid fertiliser suggestions
r/aquarium • u/redwing_blackbird_ • 1h ago
Imagine buying a male Platy to keep the Molly ladies in line. to avoid Molly mass murder 2.0, but that Platy is the biggest bitch of a Male live bearing fish ive ever seen. Ive put the meanest Molly in timeout and now my only Guppy (a female) is the male role model my tank needed 😆
the biggest bully Molly is attacking the barrier now though trying to knock it over again to attack other fish again 😭
How long should I keep her separated?? She has murder on the mind 😩
r/aquarium • u/Zestyclose-Push-5188 • 1h ago
I’ve had this tank many years just a 20 gallon planted tank with tons of plants and guppies but the last few months I’ve been dealing with hair algae it’s out competing my plants and tangling my floaters till they can’t flow freely anymore the fish aren’t eating it and I’d rather avoid chemical treatments any ideas?
r/aquarium • u/stevefrost78 • 6h ago
I'm looking to replace my internal filter with an external canister filter, and I'm a little overwhelmed with the choice.
So far I've found a few that have different options, but I'd appreciate a bit of advice going forward.
https://www.swelluk.com/swell-external-canister-filter-with-uv-clarifier
Swell branded, includes UV clarifier, seems like a bargain
https://www.swelluk.com/oase-filtosmart-thermo-external-filters#thermo-filtosmart-200
Slightly more expensive, no UV, but includes integrated heater.
https://www.swelluk.com/fluval-07-series-canister-filters#207-external-filter
Filter media options for every problem it seems.
https://www.swelluk.com/oase-biomaster-2#oase-biomaster-2-250
Includes pre-filter for easier cleaning.
There are many more too, I'm not sure if any of the features should sway me one way or another.
I like the idea of the UV clarifier, but if I choose an integrated heater, I don't have to hang one in the tank. The pre-filter on the biomaster seems like a good idea as it will save on full cleans.
This will be going in to a 200l, heavily planted tank.
(I am not affiliated with Swell, it's just the website that I happened to be browsing on.)
r/aquarium • u/fredezz • 3h ago
I've been a hobbyist for many years and only recently getting serious about a planted tank, other than replacing plants as they die.
Can someone recommend a simple but effective CO2 system along basic fertilization options.
My water is crystal clear and parameters are good...light on for 6-8 hours. Thanks in advance
r/aquarium • u/Snoo73986 • 5h ago
r/aquarium • u/A_RANDOM_ANSWER • 15h ago
I’m confused because I’m on day 6 of a fish in cycle (please don’t hate me, I inherited this fish last week without any prior notice and he was in a 1 gallon tank before I transferred him.) I started off with some seeded rocks from a fish store, and I stupidly was dosing seachem prime and not doing water changes, because from my shitty research I was told that prime detoxifies ammonia. After finding out that it doesn’t, I rushed home to do a water change, and before doing that I tested the water and the ammonia seems pretty low? I thought it would be way higher than this. Nitrite is at 0 ppm, and nitrate is tough to read but it seems like it’s between 0 and 5 ppm. Why would this be?
r/aquarium • u/aware4ever • 22h ago
The shrimp sleeps under my mystery too
r/aquarium • u/avian_bi • 1d ago
So I have this aquarium that’s basically a jungle of a whole bunch of plants, blackworms, shrimp, ostrocods and their babies (might put daphnia in too) and I’m thinking what to put in it.
The tanks dimensions are 59cm long, 28cm tall and 29cm wide.
I have loads of microfauna, but unlike other micro predators like the scarlet badis the armored sticklebacks will only eat the smallest of microfauna so the population won’t plummet.
But is my setup/tank okay for a pair or two off them?
r/aquarium • u/Happy_octian • 7h ago
Anyone can advice if this is a 0 or 0.25? Or can it be 0.5?
r/aquarium • u/Common-Wonder3635 • 15h ago
I have a 17 gallon blackwater tank i’ve had it for about 3 months and i added anchor catfish about 4 weeks ago, and just today i added glow light tetras 10 of them. And during acclamation one was swimming straight up and down, i assumed it was because of stress so i let them sit for another half a hour and when i put them in he kept swimming like that. About a hour later i cannot find him, im assuming he died. I’ve looked for about a hour and no signs of him. i’ve counted all my fish about 30 times and only count 9 i have lots of leaf litter i picked up looking for him and no luck. am i at risk for a ammonia spike? Or will the tank be able to handle it. I’m going to test my waters in the morning
r/aquarium • u/BillsInATL • 21h ago
So just over a year ago I "upgraded" from an Tetra Whisper filter to a Fluval AC30.
In the last ~18months I've now burned through 4 Fluvals. Luckily, this last one I bothered to register for warranty so we'll see how that goes.
Here's the problem: Power Outages
Living in Atlanta, between the heavy southern rain storms, old trees, and old power infrastructure, we get lots of power outages. Most just blips.
The issue is, the Fluvals NEVER recover properly on their own. If someone isnt right there to fill up the canister when the power comes on, it burns it's motor out running dry.
We just got back from a 48 hour trip. The power flickered while we were gone, but not enough to even reset the clocks. But the Fluval AC30 I bought a month ago is completely toast.
Anyone else experience this? Is there anything I can do? Am I doing something wrong because I can't believe they're selling so many of these and it's such a problem for everyone.
Thanks!
r/aquarium • u/Pure-Ad-5691 • 22h ago
I'm day 3 into it. The driftwood is starting to go down, the water is way less cloudy, and my plants haven't melted. I'm so excited!!!