Who Gives A Fish Forums

I've been struggling to keep my Discus happy in hard tap water. What's the best way to soften water without messing with their stability? My tank's 75 gallons, running a Fluval FX4, with sand substrate and a few Amazon swords. pH is around 7.8, GH 12, KH 8. They're eating well but seem a bit stressed.

Yo, try mixing RO water with your tap. That's what I do for my 55g. Keeps things steady, no wild swings. My Discus are chill now, colors poppin'. Just gotta watch the TDS, keep it under 150. I use a cheap RO buddy from Amazon, does the trick.

My LFS said peat moss in the filter works. Gonna try it next week. Tank's 40g, bare bottom, temp at 86F. Fish are small, like 3 inches. Hope it cuts the hardness without messing up the cycle.

joshito wrote: ↑Fri Jul 25, 2025 1:28 am Yo, try mixing RO water with your tap. That's what I do for my 55g. Keeps things steady, no wild swings. My Discus are chill now, colors poppin'. Just gotta watch the TDS, keep it under 150. I use a cheap RO buddy from Amazon, does the trick.

Yep, RO's the way. I mix 50/50 with tap, add a pinch of minerals back. My crew's in a 120g, planted, with driftwood. They're breeding now, so something's right. Just don't go full RO unless you're adding buffers.

I just use rain water. Free and soft. Tank's 30g, sponge filter, no plants. Fish are cool with it, but gotta test for pollutants first. My buddy lost his whole stock from acid rain once, sketchy stuff.

Peat pellets in a media bag! Drop it in your filter or hang it in the tank. My 60g's GH dropped from 10 to 6 in a week. Discus are less skittish now, eating beef heart like crazy. Just watch the tannins if you don't like the tea look.

Anyone tried those commercial softeners? Like the API stuff. My tap's a nightmare, GH 15 out the pipe. 90g tank, canister filter, temp at 84F. Don't wanna mess with RO if I can avoid it.

API's junk, bro. Tried it, fish got weird vibes. Stick to natural methods. My 75g's got driftwood, almond leaves, and I do 30% water changes twice a week with RO mix. Discus are solid, no stress bars.

Soft water's overrated. My Discus are fine in hard water, GH 10. 125g tank, FX6, planted. Just keep the temp steady and feed quality food. They've spawned twice this year.

Haterw wrote: ↑Fri Jul 25, 2025 7:35 am Soft water's overrated. My Discus are fine in hard water, GH 10. 125g tank, FX6, planted. Just keep the temp steady and feed quality food. They've spawned twice this year.

True, but wild strains need softer water. My domestics are cool with GH 8, but the Heckels I had years ago needed GH 4. Depends on the fish, I guess. 100g tank here, RO with a touch of tap, and they're thriving.