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I've been struggling to keep my alkalinity stable in my 75-gallon mixed reef. Currently dosing 10ml of Brightwell Alkalin8.3 daily but it's still dropping from 8.5 to 7.2 dKH every 48 hours. Anyone got a better dosing schedule or product recs? Tank's got LPS, a few SPS, and a pair of clowns. Running Radion XR15s, 78°F, salinity at 1.025.

You might need to up your dosing frequency. I had similar issues in my 120-gallon until I split the dose into twice daily, 5ml every 12 hours. Also, check your magnesium levels, low Mg can make alk bounce around. I use ESV B-Ionic two-part now, way more stable than Brightwell for me.

robson wrote: ↑Sat Jul 19, 2025 12:09 pm You might need to up your dosing frequency. I had similar issues in my 120-gallon until I split the dose into twice daily, 5ml every 12 hours. Also, check your magnesium levels, low Mg can make alk bounce around. I use ESV B-Ionic two-part now, way more stable than Brightwell for me.

Yep, seconding the magnesium check. My alk was all over until I got Mg up to 1350. Now I dose 8ml of B-Ionic at 8am and 8pm, keeps it rock solid at 8.8.

My nano's alk drops like crazy too. Gonna try splitting doses like you guys said. Using Red Sea foundation right now but maybe time to switch. Got a Duncan and some zoas that look pissed when alk swings.

Ditch the Brightwell, man. That stuff's sketchy for alk stability. I switched to Tropic Marin All-for-Reef last year and never looked back. Dosing 15ml/day in my 90-gallon, holds 8.5 dKH like clockwork. Also, what's your calcium at? If it's low, alk's gonna crash faster.

Thanks for the tips, everyone. I'll test Mg and Ca tonight and look into splitting doses or switching products. Appreciate the real-world experiences.

Auric12 wrote: ↑Sat Jul 19, 2025 3:42 pm Ditch the Brightwell, man. That stuff's sketchy for alk stability. I switched to Tropic Marin All-for-Reef last year and never looked back. Dosing 15ml/day in my 90-gallon, holds 8.5 dKH like clockwork. Also, what's your calcium at? If it's low, alk's gonna crash faster.

All-for-Reef is solid, but it's pricier than two-part. If budget's tight, ESV or Red Sea two-part with a dosing pump works nearly as well. Just gotta dial it in over a week or two.

For real on the dosing pump. Got a Kamoer X1 last month and it's a game-changer. Set it to dose 2ml every 3 hours and my alk hasn't budged from 8.6 in weeks. Torches and acans are finally coloring up right.

Man, all this talk makes me wanna upgrade to a bigger tank. My 20-gallon's a pain to balance. Maybe time to cut it and go 50+ gallons for stability.

flux_42 wrote: ↑Sat Jul 19, 2025 8:01 pm Man, all this talk makes me wanna upgrade to a bigger tank. My 20-gallon's a pain to balance. Maybe time to cut it and go 50+ gallons for stability.

Bigger water volume definitely helps buffer swings, but nanos can work if you're diligent. My buddy keeps a 15-gallon with daily 1-liter water changes instead of dosing. His SPS grow slower but never have alk issues.