Betta fish and water hardness

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Lacey
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Joined: Sun Jan 07, 2024 10:11 am

Betta fish and water hardness

Post by Lacey »

So I've been testing my water lately and the hardness is kinda high. My betta seems fine but I'm worried it might mess with him long term. Anyone got tips on how to lower it without stressing him out? Tank's a 5 gallon, planted, with a sponge filter. He's been in there about 3 months.
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guppyzone
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Joined: Thu Oct 10, 2024 1:07 am

Re: Betta fish and water hardness

Post by guppyzone »

Yep, high hardness can be sketchy for bettas. I'd start with partial water changes using RO or distilled water, mixed with your tap. That's what I do for my guys. Also, driftwood can help a bit, but it's slow. What's your GH and KH at right now?
kalixi
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Joined: Thu Oct 10, 2024 10:08 pm

Re: Betta fish and water hardness

Post by kalixi »

guppyzone wrote: Wed Jun 04, 2025 9:31 pm Yep, high hardness can be sketchy for bettas. I'd start with partial water changes using RO or distilled water, mixed with your tap. That's what I do for my guys. Also, driftwood can help a bit, but it's slow. What's your GH and KH at right now?
Adding to this, Indian almond leaves can help too. They release tannins that soften water and give a more natural vibe. Just don't go overboard or your tank will look like tea.
sailorby
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Joined: Thu Oct 10, 2024 8:20 pm

Re: Betta fish and water hardness

Post by sailorby »

Hardness isn't always a dealbreaker if it's stable. Bettas can adapt to a range, but sudden changes are bad. If you're set on lowering it, do it gradually. RO water is your best bet, but remember to remineralize slightly so it's not too soft. What's your current pH? That can affect how hardness impacts your fish.
keel
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Joined: Thu Oct 10, 2024 6:54 pm

Re: Betta fish and water hardness

Post by keel »

My water's hard too, but my betta's been chill. I just do regular water changes and he's fine. Maybe it's not as big a deal as we think?
Lacey
Posts: 6
Joined: Sun Jan 07, 2024 10:11 am

Re: Betta fish and water hardness

Post by Lacey »

Thanks for the advice, everyone. My GH is around 10 dGH and KH is 6. pH is 7.4. I'll try the RO water mix and maybe some almond leaves. Appreciate the help!
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guppyzone
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Re: Betta fish and water hardness

Post by guppyzone »

Lacey wrote: Thu Jun 05, 2025 12:52 am Thanks for the advice, everyone. My GH is around 10 dGH and KH is 6. pH is 7.4. I'll try the RO water mix and maybe some almond leaves. Appreciate the help!
No prob! Just go slow with the changes, like sailorby said. Bettas hate sudden swings. Keep us posted on how it goes.
kalixi
Posts: 5
Joined: Thu Oct 10, 2024 10:08 pm

Re: Betta fish and water hardness

Post by kalixi »

Yeah, 10 dGH isn't crazy high, but if you wanna lower it, the RO mix is the way. Just don't forget to test often so you don't overshoot. And yeah, almond leaves are great for their immune system too.
sailorby
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Joined: Thu Oct 10, 2024 8:20 pm

Re: Betta fish and water hardness

Post by sailorby »

keel wrote: Wed Jun 04, 2025 11:11 pm My water's hard too, but my betta's been chill. I just do regular water changes and he's fine. Maybe it's not as big a deal as we think?
It's true some bettas tolerate it better than others. Genetics play a role. But if you're breeding or dealing with finicky fish, softer water can help. For most pets, stability matters more than perfect numbers.
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