Discus water hardness explained

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paddlepop
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Joined: Mon Jan 31, 2022 5:52 pm

Discus water hardness explained

Post by paddlepop »

So I've been keeping Discus for about six months now, and I'm still kinda confused about water hardness. My tap water's GH is around 8, KH is 6, and pH sits at 7.2. I do 30% water changes twice a week with aged tap water. Are these numbers gonna cut it, or do I need to mess with RO water? Tank's a 75-gallon with sand substrate, sponge filters, and a bunch of driftwood. Fish seem chill but not growing as fast as I'd like.
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barks
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Re: Discus water hardness explained

Post by barks »

Your GH and KH are fine for Discus, honestly. They're adaptable as long as params stay stable. RO water's overkill unless you're breeding. Focus on temp (86°F), clean water, and quality food. What's your feeding routine? Mine get frozen bloodworms, beef heart mix, and pellets twice a day. Growth issues might be diet-related, not hardness.
Astrid
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Joined: Sun Aug 04, 2024 12:36 pm

Re: Discus water hardness explained

Post by Astrid »

barks wrote: Fri May 02, 2025 1:45 am Your GH and KH are fine for Discus, honestly. They're adaptable as long as params stay stable. RO water's overkill unless you're breeding. Focus on temp (86°F), clean water, and quality food. What's your feeding routine? Mine get frozen bloodworms, beef heart mix, and pellets twice a day. Growth issues might be diet-related, not hardness.
Agreed. Stability trumps chasing "perfect" numbers. I've kept Discus in harder water (GH 10) for years with no issues. Key is consistent water changes and avoiding sudden shifts. What's your nitrate level? High nitrates can stunt growth more than hardness.
hanksid
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Re: Discus water hardness explained

Post by hanksid »

My tap's similar to yours, paddlepop. I just add a bit of peat to my filter to soften it slightly. Fish are thriving, no RO needed. Tank's planted with Amazon swords and vals, which seem to help buffer things. How often do you test your water? I check weekly with the API kit.
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kadyash
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Re: Discus water hardness explained

Post by kadyash »

RO water's a scam unless you're trying to breed show-quality fish. Your setup sounds solid, mate. Maybe bump up feeding? My crew gets six small meals a day. Also, what's your stock like? Overcrowding can mess with growth rates. I keep six in a 90-gallon with cardinal tetras and rams.
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seaquake
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Re: Discus water hardness explained

Post by seaquake »

I dunno, man. My LFS swears by RO for Discus, but my wallet says nope. I'm using tap with Seachem Equilibrium to tweak minerals. Tank's got a Fluval canister, temp at 84°F, and the fish are coloring up nicely. Maybe your issue's more about genetics than water?
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3monkeys
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Re: Discus water hardness explained

Post by 3monkeys »

kadyash wrote: Fri May 02, 2025 4:52 am RO water's a scam unless you're trying to breed show-quality fish. Your setup sounds solid, mate. Maybe bump up feeding? My crew gets six small meals a day. Also, what's your stock like? Overcrowding can mess with growth rates. I keep six in a 90-gallon with cardinal tetras and rams.
Exactly. Wild-caught Discus might need softer water, but domestics are bred to tolerate harder conditions. Focus on cleanliness and diet. What's your water change schedule like? I do 50% weekly with a Python, and my group's growing like weeds.
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paddlepop
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Re: Discus water hardness explained

Post by paddlepop »

Thanks for the input, everyone. Sounds like I'm overthinking the hardness thing. Gonna up the feeding to three times a day and stick with my current water routine. Nitrates are under 10ppm, so that's not the issue. Appreciate the advice!
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