Managing pH in freshwater tanks

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knightboy
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Joined: Fri Sep 08, 2023 1:19 pm

Managing pH in freshwater tanks

Post by knightboy »

My pH keeps dropping below 6.0 in my 20-gallon planted tank. I've got driftwood and almond leaves in there, but it's still too acidic for my Neon Tetras. Anyone dealt with this before?
boulder
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Joined: Thu Oct 10, 2024 3:50 pm

Re: Managing pH in freshwater tanks

Post by boulder »

Yep, driftwood and leaves will do that. You could try adding some crushed coral in a media bag near your filter. It'll slowly raise the pH without shocking your fish. How often are you doing water changes?
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terrac
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Joined: Sat May 25, 2024 5:07 pm

Re: Managing pH in freshwater tanks

Post by terrac »

Crushed coral works, but you'll need to monitor KH too. If your water's too soft, the pH will keep crashing. Test your KH and GH—if they're below 3 dKH, consider adding a remineralizer like Seachem Equilibrium.
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rivernox
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Re: Managing pH in freshwater tanks

Post by rivernox »

I had the same prob in my 40 breeder. Cut the leaves, added coral, and now it's chill at 6.8. Tetras are vibin'. Gonna test KH like terrac said tho, just in case.
knightboy
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Joined: Fri Sep 08, 2023 1:19 pm

Re: Managing pH in freshwater tanks

Post by knightboy »

Thanks for the tips. I'll grab some coral and test KH. Water changes are weekly, 25%, with RO water. Maybe I need to switch to tap.
sgdiscus
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Joined: Thu Oct 10, 2024 9:29 pm

Re: Managing pH in freshwater tanks

Post by sgdiscus »

RO water's the issue. No minerals at all. Tap's better if it's safe where you live.
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DuskRider9
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Re: Managing pH in freshwater tanks

Post by DuskRider9 »

My pH was all over till I stopped using RO. Now I mix tap and RO, 50/50. Works great.
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Breezey
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Re: Managing pH in freshwater tanks

Post by Breezey »

rivernox wrote: Mon Jun 16, 2025 3:49 am I had the same prob in my 40 breeder. Cut the leaves, added coral, and now it's chill at 6.8. Tetras are vibin'. Gonna test KH like terrac said tho, just in case.
Same here, but I left one leaf for the tannins. Fish seem happier with a bit of both.
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terrac
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Re: Managing pH in freshwater tanks

Post by terrac »

Mixing tap and RO is a solid plan if your tap's too hard. Just remember to condition it. What's your tap pH and KH?
boulder
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Joined: Thu Oct 10, 2024 3:50 pm

Re: Managing pH in freshwater tanks

Post by boulder »

terrac wrote: Mon Jun 16, 2025 5:43 am Mixing tap and RO is a solid plan if your tap's too hard. Just remember to condition it. What's your tap pH and KH?
Yeah, and if tap's sketchy, a good conditioner like Prime will handle chlorine and heavy metals.
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