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Water parameters: pH, GH, KH
Posted: Tue Jun 24, 2025 2:40 pm
by brooklynite
My tap water's pH is 8.2, GH around 300 ppm, KH 180 ppm. Gonna set up a new tank for Discus but heard they need softer water. How do y'all adjust these params without messing with stability too much? Got a 75 gallon, planning on sand substrate and driftwood.
Re: Water parameters: pH, GH, KH
Posted: Tue Jun 24, 2025 3:26 pm
by tidesur
That's pretty hard water for Discus. I'd recommend mixing with RO water to lower GH and KH. Start with a 50/50 mix and test. Also, driftwood helps lower pH naturally over time. What's your filtration setup? A good canister filter will help maintain stability.
Re: Water parameters: pH, GH, KH
Posted: Tue Jun 24, 2025 4:18 pm
by onyxid
tidesur wrote: ↑Tue Jun 24, 2025 3:26 pm
That's pretty hard water for Discus. I'd recommend mixing with RO water to lower GH and KH. Start with a 50/50 mix and test. Also, driftwood helps lower pH naturally over time. What's your filtration setup? A good canister filter will help maintain stability.
Agreed on the RO mix. Just don't change more than 20% at a time or you'll shock the fish. What's your current tank temp? Discus need it around 82-86°F.
Re: Water parameters: pH, GH, KH
Posted: Tue Jun 24, 2025 5:04 pm
by bricklane
Yeah, RO's the way to go. I run mine through a peat filter first to soften it up. Also, keep an eye on your KH, 'cause if it drops too low, your pH might crash. How often you planning water changes? With Discus, I do 30% twice a week.
Re: Water parameters: pH, GH, KH
Posted: Tue Jun 24, 2025 5:44 pm
by michelbak
Man, I tried Discus in hard water once. Total disaster. They just sat there looking miserable. RO water and driftwood saved my sanity. Also, don't forget to age your water before adding it to the tank. Chloramine's a killer.
Re: Water parameters: pH, GH, KH
Posted: Tue Jun 24, 2025 6:29 pm
by Flynnex
What's RO water? Never heard of it. I've got a 55 gallon with tap water and my fish seem fine. But I'm just keeping Tetras and Corys, not Discus.
Re: Water parameters: pH, GH, KH
Posted: Tue Jun 24, 2025 6:42 pm
by oceanode
RO is reverse osmosis water. It's filtered to remove minerals. You can buy it or get a unit to make it at home. For Discus, it's pretty much a must if your tap water's hard.
Re: Water parameters: pH, GH, KH
Posted: Tue Jun 24, 2025 7:38 pm
by brooklynite
Thanks for the advice, everyone. Gonna start with the RO mix and driftwood. Got an Eheim canister filter and planning to keep the temp at 84°F. Will test the water daily during the transition.
Re: Water parameters: pH, GH, KH
Posted: Tue Jun 24, 2025 7:50 pm
by tidesur
Sounds like a solid plan. Just remember, stability's key with Discus. They're not fans of sudden changes. What's your stocking plan? Overcrowding can mess with your params too.
Re: Water parameters: pH, GH, KH
Posted: Tue Jun 24, 2025 8:11 pm
by onyxid
tidesur wrote: ↑Tue Jun 24, 2025 7:50 pm
Sounds like a solid plan. Just remember, stability's key with Discus. They're not fans of sudden changes. What's your stocking plan? Overcrowding can mess with your params too.
Yep, and don't forget to quarantine new fish. Last thing you need is introducing disease while you're dialing in the water.