Who Gives A Fish Forums

My discus tank has been struggling with algae lately. I do weekly 50% water changes, use RO water, and keep the temp at 84°F. The tank is 75 gallons with sand substrate and driftwood. Lighting is on for 8 hours a day. Any tips to control the algae without harming the fish?

I had the same issue last month. Cut the light to 6 hours and added some nerite snails. They're doing a solid job cleaning up the glass. Also, check your feeding routine, overfeeding can mess with the algae growth.

What's your nitrate level? High nitrates can fuel algae. I keep mine below 10ppm with more frequent water changes and floating plants like frogbit. They shade the tank and suck up excess nutrients.

Sunnyday wrote: ↑Wed Apr 30, 2025 3:07 pm What's your nitrate level? High nitrates can fuel algae. I keep mine below 10ppm with more frequent water changes and floating plants like frogbit. They shade the tank and suck up excess nutrients.

Agreed. I also use a UV sterilizer, it's been a game-changer for green water algae. Just make sure it's sized correctly for your tank volume.

yo, try dimmin' the lights or gettin' a timer. my algae prob went way down when i stopped blastin' the tank all day. also, feed less, like way less, they don't need as much as u think.

I've had luck with Siamese algae eaters. They're chill with discus and gobble up the algae. Just don't get the fake ones, some stores sell lookalikes that don't eat algae. Also, maybe tweak your light spectrum if you can.

How old are your bulbs? Older bulbs can shift spectrum and promote algae. I replace mine every 6 months. Also, consider adding more fast-growing plants like hornwort to outcompete the algae.

Dude, blackout for a couple days. Cover the tank, no light at all. It's sketchy but works. Just keep an eye on the fish and do a big water change after. Also, check your phosphate levels, they're sneaky algae boosters.

Boldly wrote: ↑Wed Apr 30, 2025 8:12 pm Dude, blackout for a couple days. Cover the tank, no light at all. It's sketchy but works. Just keep an eye on the fish and do a big water change after. Also, check your phosphate levels, they're sneaky algae boosters.

I'd be careful with blackouts, discus can stress easily. Maybe try reducing light gradually instead. And yes, phosphates are key, I test mine weekly now.

Thanks for all the advice, everyone. I'll start with reducing light and checking nitrates and phosphates. Appreciate the help!