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cyanobacteria in coral tank woes
Posted: Fri Jun 06, 2025 3:05 am
by trailblaz0r
Been battling cyanobacteria in my 75g mixed reef for weeks now. Tried manual removal, reduced feeding, even blackouts, but it keeps coming back. Running two AI Primes, 0 ammonia, 0 nitrite, 5 nitrate, 8 dKH. Any long-term fixes that won't nuke my Acros?
Re: cyanobacteria in coral tank woes
Posted: Fri Jun 06, 2025 3:46 am
by dunamis
Had the same issue last year. What's your phosphate level? Cyano thrives when there's an imbalance between nitrate and phosphate. If it's undetectable, try dosing NeoPhos to 0.03 ppm while keeping nitrates around 5. Also, increase flow in dead zones with a cheap wavemaker.
Re: cyanobacteria in coral tank woes
Posted: Fri Jun 06, 2025 4:35 am
by clawmaster
dunamis wrote: ↑Fri Jun 06, 2025 3:46 am
Had the same issue last year. What's your phosphate level? Cyano thrives when there's an imbalance between nitrate and phosphate. If it's undetectable, try dosing NeoPhos to 0.03 ppm while keeping nitrates around 5. Also, increase flow in dead zones with a cheap wavemaker.
Yep, flow's key. I added a Jebao SLW-20 to my back corner and cyano cleared in two weeks. Just don't go ham with the GFO, or you'll crash your phosphates again.
Re: cyanobacteria in coral tank woes
Posted: Fri Jun 06, 2025 5:25 am
by alohavibes
My 40g breeder had cyano after I switched salts. Tested everything, turned out my RODI filter was shot. TDS was 12. Replaced the cartridges and did three 20% changes over a week. Cyano's gone now. Maybe check your water source?
Re: cyanobacteria in coral tank woes
Posted: Fri Jun 06, 2025 5:31 am
by mander
Seconding flow adjustments. Also, what's your cleanup crew like? I added 10 more Trochus snails and they graze on the cyano film. Not a full fix, but helps between water changes.
Re: cyanobacteria in coral tank woes
Posted: Fri Jun 06, 2025 6:57 am
by copperkit
Weird vibe, but my cyano vanished after I stopped using Brightwell CoralAmino. Started dosing AcroPower instead. Dunno if it's coincidence, but maybe check your additives?
Re: cyanobacteria in coral tank woes
Posted: Fri Jun 06, 2025 8:49 am
by trailblaz0r
Thanks for the tips, all. Phosphate was 0.01 last I checked. Gonna test the RODI, bump flow with an old MP10, and grab some Trochus snails this weekend. Will report back.
Re: cyanobacteria in coral tank woes
Posted: Fri Jun 06, 2025 10:26 am
by dolido
My LFS said cyano's normal in new tanks. Mine's 4 months old. Should I just wait it out?
Re: cyanobacteria in coral tank woes
Posted: Fri Jun 06, 2025 11:04 am
by dunamis
dolido wrote: ↑Fri Jun 06, 2025 10:26 am
My LFS said cyano's normal in new tanks. Mine's 4 months old. Should I just wait it out?
Nope, that's a myth. New tanks get diatoms, not cyano. If it's red and slimy, act now. Check your nitrates, phosphates, and flow like we've been saying.
Re: cyanobacteria in coral tank woes
Posted: Fri Jun 06, 2025 12:23 pm
by airtys
I used ChemiClean once. Worked fast but my Zoas closed up for days. Wouldn't recommend unless it's real bad.