Dear Bailey,

I'm writing to you because I'm at my wit's end. My aquarium has become a swamp. I started with a beautiful 20-gallon tank with colorful fish and pristine gravel, and now it looks like something from a nature documentary about pond life. Green algae coats every surface — the glass, the plants, the decorations, even my poor fish look like they're wearing fuzzy green sweaters. I've tried cleaning it constantly, but the algae just comes back stronger, like some kind of underwater villain with a vendetta against me. My friends won't even come over anymore. What am I doing wrong?

Sincerely,

The Swamp Thing

Dear Swamp Thing,

First of all, thank you for writing. Second, I have to tell you that as a German Shepherd, I find it hilarious that you're struggling with an aquatic ecosystem when I can barely figure out why my water bowl keeps tipping over. But I've done my research, and I'm here to help.

Here's the thing about algae blooms: they're not a sign that you're a failure at aquarium maintenance. They're actually a sign that your tank is too good at one thing — producing excess nutrients. Think of it like this: if someone kept refilling my food bowl beyond what I need, I wouldn't suddenly become a well-adjusted pup. I'd just get rounder and more unpleasant. Your algae feels the same way about excess light and nitrates.

Let's start with the obvious culprit: light. Most people keep their aquarium lights on way too long. Those algae spores are basically doing the photosynthesis equivalent of binge-watching Netflix. I recommend keeping your lights on for eight to ten hours maximum. That's right — your fish need darkness more than my teenager needs sleep, which is saying something. If your tank sits near a window getting natural sunlight, move it. Trust me on this one.

Next up is feeding. I know you probably think your fish are giving you sad eyes asking for more food, but they're lying. Fish are professional manipulators. Feed them once or twice a day, only what they can consume in a few minutes. Uneaten food decays and creates nitrates, which algae loves more than I love chasing squirrels. Overfeeding is basically you creating an all-you-can-eat buffet for the green menace.

Speaking of nitrates, you need to get a water test kit immediately. If your nitrate levels are above 20 parts per million, that's your smoking gun. High nitrates mean you're not doing enough water changes. I'd suggest 25 to 30 percent weekly water changes. Yes, this is work. No, there's no way around it. Consider it your penance for creating the Swamp Thing in the first place.

Now for the fun part: fighting back. Invest in some algae-eating fish or invertebrates. Plecos are popular, though some varieties get enormous, so do your research. Amano shrimp are excellent algae controllers and less likely to destroy your plants. Otocinclu fish are small and efficient. You're basically hiring a cleaning crew, which is something I fully support because I certainly won't do it.

For immediate relief, do a manual cleaning. Use an algae scraper on the glass and remove affected decorations. Don't use any chemicals unless you're using products specifically designed for aquariums — regular cleaners will poison your fish faster than a tennis ball can distract a dog.

Finally, add some live plants. They compete with algae for nutrients and light, plus they make your tank look less like a primordial swamp and more like an actual aquatic home. Faster-growing plants like stem plants work best.

The bottom line, Swamp Thing, is that algae is a symptom, not the disease itself. Find the root cause — usually light and nutrients — and you'll solve this. Your friends will return. Your fish will no longer need exfoliating treatments. And you'll sleep better at night.

Best of luck,

Bailey

Ask the Pet is a friendly advice column written by Bailey, a German Shepherd with endless enthusiasm and a heart of gold. Each installment answers a submitted pet dilemma with warm, earnest, tail-wagging guidance. The tone is wholesome and lighthearted, pairing genuinely useful tips with Bailey's irrepressible good cheer. Send your questions for Bailey to [email protected].