Discus fry tank water testing

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bowsar
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Joined: Wed Jan 26, 2022 3:34 am

Discus fry tank water testing

Post by bowsar »

My Discus fry aren't growing like they should. I've got a 20-gallon tank, 0 ammonia, 0 nitrite, 5 ppm nitrate, pH 6.8, temp at 84°F. Using a sponge filter and doing 50% water changes daily. Feeding them baby brine shrimp 4 times a day. Any ideas what's up?
flashy
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Joined: Tue Feb 20, 2024 10:18 am

Re: Discus fry tank water testing

Post by flashy »

bowsar wrote: Tue Aug 26, 2025 3:26 am My Discus fry aren't growing like they should. I've got a 20-gallon tank, 0 ammonia, 0 nitrite, 5 ppm nitrate, pH 6.8, temp at 84°F. Using a sponge filter and doing 50% water changes daily. Feeding them baby brine shrimp 4 times a day. Any ideas what's up?
Your params sound solid, but fry need more than just clean water. Try adding a bit of crushed flake or powdered spirulina to their diet. Also, check your TDS—too low can stunt growth. Aim for 100-150 ppm with a mix of RO and tap.
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Blaze
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Re: Discus fry tank water testing

Post by Blaze »

Yo, my fry tank's a mess. Got a 10-gallon, no plants, just a hang-on-back filter. Water's kinda cloudy, but the fish seem chill. Should I be testing more than just ammonia?
WiseLynx
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Re: Discus fry tank water testing

Post by WiseLynx »

Testing nitrite and nitrate is crucial. Cloudy water suggests a bacterial bloom, which can mess with oxygen levels. Upgrade to a sponge filter if you can, and cut back on feeding for a couple days.
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bowsar
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Re: Discus fry tank water testing

Post by bowsar »

flashy wrote: Tue Aug 26, 2025 5:21 am
bowsar wrote: Tue Aug 26, 2025 3:26 am My Discus fry aren't growing like they should. I've got a 20-gallon tank, 0 ammonia, 0 nitrite, 5 ppm nitrate, pH 6.8, temp at 84°F. Using a sponge filter and doing 50% water changes daily. Feeding them baby brine shrimp 4 times a day. Any ideas what's up?
Your params sound solid, but fry need more than just clean water. Try adding a bit of crushed flake or powdered spirulina to their diet. Also, check your TDS—too low can stunt growth. Aim for 100-150 ppm with a mix of RO and tap.
Thanks for the tip! Gonna grab some spirulina powder tomorrow. Never thought about TDS before—my tap's pretty soft, so that might be it.
flashy
Posts: 11
Joined: Tue Feb 20, 2024 10:18 am

Re: Discus fry tank water testing

Post by flashy »

bowsar wrote: Tue Aug 26, 2025 7:21 am
flashy wrote: Tue Aug 26, 2025 5:21 am
bowsar wrote: Tue Aug 26, 2025 3:26 am My Discus fry aren't growing like they should. I've got a 20-gallon tank, 0 ammonia, 0 nitrite, 5 ppm nitrate, pH 6.8, temp at 84°F. Using a sponge filter and doing 50% water changes daily. Feeding them baby brine shrimp 4 times a day. Any ideas what's up?
Your params sound solid, but fry need more than just clean water. Try adding a bit of crushed flake or powdered spirulina to their diet. Also, check your TDS—too low can stunt growth. Aim for 100-150 ppm with a mix of RO and tap.
Thanks for the tip! Gonna grab some spirulina powder tomorrow. Never thought about TDS before—my tap's pretty soft, so that might be it.
Yep, soft water's tricky. Mix in a bit of crushed coral or add a mineral supplement to bump up the TDS. Just go slow—big swings stress them out.
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Blaze
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Joined: Fri Apr 26, 2024 10:31 pm

Re: Discus fry tank water testing

Post by Blaze »

WiseLynx wrote: Tue Aug 26, 2025 7:02 am Testing nitrite and nitrate is crucial. Cloudy water suggests a bacterial bloom, which can mess with oxygen levels. Upgrade to a sponge filter if you can, and cut back on feeding for a couple days.
Got it. Ordered a test kit and a sponge filter. Gonna skip feeding tomorrow and see if it clears up. Thanks!
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