greyhunter
Community Member
I’m having some weird long term issues with certain zoas and wanted to see if anyone has experienced something similar.
Some zoas only open half or fully open intermittently. Examples are:
Most of these had a noticeable growth spurt at first and then suddenly stopped growing completely.
The weirdest one is my Rastas. They seem to go through a repeating cycle:
Meanwhile, my Rainbow Incinerator zoas are growing extremely well with no issues at all.
Other zoas like:
have basically not grown since I added them back in October, although they are open most of the time.
Current parameters:
PAR is around 80–90 where the zoas are placed.
What’s confusing me is that literally all my other corals not only look healthy, but are also actively growing well:
I also don’t see any pests or signs of pests on the zoas.
Flow in the tank comes from a wavemaker together with an RFG nozzle.
Filtration/setup:
Additives/feeding:
Does anyone have an idea what could specifically irritate certain zoa varieties while others thrive? Could it be phosphate related, bacterial irritation, trace imbalance, lighting, flow, or just certain morphs being sensitive?
Some zoas only open half or fully open intermittently. Examples are:
- Rastas
- Utter Chaos
- Generic orange zoas
- Lime green zoas
- Gorilla Nipple zoas
Most of these had a noticeable growth spurt at first and then suddenly stopped growing completely.
The weirdest one is my Rastas. They seem to go through a repeating cycle:
- 1–2 polyps stay open
- the polyps slowly get smaller
- then fully close and become dull/faded
- after a few weeks they recover and open again
- then the whole cycle repeats
Meanwhile, my Rainbow Incinerator zoas are growing extremely well with no issues at all.
Other zoas like:
- Sunny D
- Orange Mandarin
- Fruit Loops
- Screaming Eagle
- Tutti Frutti
have basically not grown since I added them back in October, although they are open most of the time.
Current parameters:
- Alk: 8 dKH
- Calcium: 420 ppm
- Magnesium: 1290 ppm
- pH daytime: 8.3
- pH nighttime: 8.0
- NO3: 5 ppm
- PO4: 0.25 ppm
PAR is around 80–90 where the zoas are placed.
What’s confusing me is that literally all my other corals not only look healthy, but are also actively growing well:
- Micromussa
- Kenya tree
- Toadstool
- Mushrooms
- Forest Fire Monti
- Stylophora
- Sinularia
I also don’t see any pests or signs of pests on the zoas.
Flow in the tank comes from a wavemaker together with an RFG nozzle.
Filtration/setup:
- 2 sponges
- Filter floss (used to change weekly, now every 3 days)
- Aquaforest active carbon
- 15% weekly water changes with Tropic Marin Pro
Additives/feeding:
- AB+ 3x per week
- Aquaforest Life Source once a week
- Occasional Reef Roids feeding
Does anyone have an idea what could specifically irritate certain zoa varieties while others thrive? Could it be phosphate related, bacterial irritation, trace imbalance, lighting, flow, or just certain morphs being sensitive?
