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I've got a 55 gallon planted tank with a bunch of Discus and some Corydoras. The water's been stable, 0 ammonia, 0 nitrite, nitrate around 10 ppm. I'm thinking of adding API Bio-Chem Stars to the filter, but not sure how many to use. The box says 1 per 10 gallons, but I've heard mixed things. Anyone got experience with these?

I've used Bio-Chem Stars in my 40 breeder, and they're pretty solid. Started with 4 like the box says, but bumped it to 5 after a month. My nitrates dropped from 20 to 5 ppm, so it's worth messing with. How often do you do water changes?

brisk wrote: ↑Mon Jun 09, 2025 11:35 am I've used Bio-Chem Stars in my 40 breeder, and they're pretty solid. Started with 4 like the box says, but bumped it to 5 after a month. My nitrates dropped from 20 to 5 ppm, so it's worth messing with. How often do you do water changes?

I'd stick with the recommended amount first. Overloading can mess with the bio balance. What's your filter flow rate? High flow might need more stars to keep up.

Yo, I run a 75 with heavy stock and use 8 stars. Nitrates stay chill, like 5 ppm max. But my tank's got a FX6, so the flow's nuts. If your filter's weaker, maybe cut it back to 6. How's your plant load?

Thanks for the input, everyone. I do weekly 30% water changes, and the filter's a Fluval 407. Plants are decent, mostly Anubias and Java Fern. I'll start with 5 and monitor.

Sounds like a plan. The 407's got good flow, so 5 should work. Keep an eye on the nitrates after a couple weeks. If they creep up, toss in another one.

raysun wrote: ↑Mon Jun 09, 2025 12:28 pm Yo, I run a 75 with heavy stock and use 8 stars. Nitrates stay chill, like 5 ppm max. But my tank's got a FX6, so the flow's nuts. If your filter's weaker, maybe cut it back to 6. How's your plant load?

Flow's key here. The 407's around 380 GPH, so 5–6 stars should cover it. Heavy planting helps with nitrates too, so you might not need as many.

Yep, plants eat up nitrates like crazy. My floaters gobble that stuff up. If your Anubias are thriving, you might not even need the full 5. Test weekly and adjust.