Why are my corals not thriving?

[oceanblue]

My corals aren't growing like they used to. I have a 50-gallon tank with Zoanthids, Acans, and a Duncan. Water params are good, 0 ammonia, 0 nitrite, 5 nitrate, 8.2 pH, 1.025 salinity. Running two AI Prime lights, 10 hours a day. Weekly 10% water changes with Red Sea Coral Pro. What's going on?

[stellaBay]

Have you checked your alkalinity and calcium levels? Those are critical for coral growth. Also, how old are your lights? LEDs can lose intensity over time.

[landonix]

Have you checked your alkalinity and calcium levels? Those are critical for coral growth. Also, how old are your lights? LEDs can lose intensity over time.

Yep, stellaBay's spot on. I'd test alk, calcium, and magnesium. If those are off, it's gonna mess with growth. My Duncan stalled when my alk dropped to 6 dKH.

[southern]

Dang, my Zoas been actin' weird too. Tank's at 78 degrees, got a Fluval heater. Maybe it's the temp swing? My buddy's tank runs cooler and his stuff's poppin'.

[creekmaster]

Temp stability matters, but 78 is fine if it's consistent. How's your flow? Acans and Duncans like moderate movement. Too much or too little can stress 'em out.

[rodcatch22]

I'd also look at your feeding routine. Are you spot-feeding the Duncan? They're greedy little guys. Try mysis or reef roids a couple times a week.

[carina]

I'd also look at your feeding routine. Are you spot-feeding the Duncan? They're greedy little guys. Try mysis or reef roids a couple times a week.

Totally agree. My Acans perked up when I started target-feeding. Also, how's your phosphate? High phosphates can block calcification.

[novatar]

Yo, my tank was strugglin' till I cut back the light cycle. Maybe dial it down to 8 hours? Some corals get stressed with too much light, even if the params are chill.

[yorklan]

Have you introduced anything new lately? Sometimes corals react to chemical warfare from others. A carbon filter might help if that's the case.

[guppy]

Have you introduced anything new lately? Sometimes corals react to chemical warfare from others. A carbon filter might help if that's the case.

Good point. Also, check for pests like flatworms or nudibranchs. They can sneak in and wreak havoc without you noticing.