Montipora polyps beginning to bleach?

[tim132]

Just spotted a couple of white spots on the Monti today and upon a closer zoom it looks like polyps beginning to bleach? Still new to reefing and haven't experienced STN or RTN before.

This piece has doubled in size since it's been in the tank (4 months).

- Alk 8.5
- Calcium 470
- Mag 1350
- Nitrate 2.5 (low nutrients due to fallow period a possible issue?)
- Po4 0.03
- Currently 6 weeks into a fallow period
- Vipraspectra 165 - ch1 80% (11:00 - 20:30) ch2 10% (13:00 - 18:30)

Any help would be appreciated guys!!

 

[Ludders]

usually alk swings cause that, but monti's are very hardy and will recover.
Have you changed your alk dosing lately or buffered up, or changed anything else recently?

 

[tim132]

Thanks for the reply Ludders, really appreciate it! ✌

My alk is usually very stable but now I think about it the other day I filled my ato (kalk) up and forgot to turn it back on after 30 minutes.

Turned it on a couple of hours later and it blasted a load of lime water into the tank. That's likely the cause I bet!

I'm glad to hear it'll likely recover though.

Would it be wise to drop my alkalinity a bit lower as I'm struggling to raise nutrients during the fallow period?

 

[Ludders]

I would suggest maintaining its current level. Why are you having a fallow period? I would probably still broadcast feed the tank with a powder coral food to help keep your nutrients up a bit.
The low nitrate isn't harmful to coral, it just means there's less for them to feed off and will slow them down.
Think of the ocean, nitrate levels are not around 2-3 ppm, more a fraction of these levels us reefers aim to achieve. Partly why they can be destroyed in a short space of time and take so many more years to recover.

 

[tim132]

I had an ich/velvet outbreak unfortunately. Nothing wet is going in there unquarantined going forward!

Yeah, I feed reefroids/frozen at least every other day, often once a day. Fuge off and skimmer off, 10% WC a month (during fallow) and still struggling with raising nutrients. It's crazy!

I understand the nitrates are at a good level but I read about alk burn affecting corals when alkalinity is above 8dkh in ULNS, that's what made me ask about that.

 

[Ludders]

Ah I see, 8.5 is good I would maintain current levels. How long you going fallow for? 6-8 weeks?

 

[tim132]

Excellent thanks for that!!

At the moment I'm aiming for 10 weeks and then decide from there if I want to stretch it out to the 12 weeks! ATM 10 weeks seems ample, but you can never be sure can you.

6 weeks in now, over the hump thank god!

 

[Ludders]

Yeah definitely, sorry to hear about your issue. Did you lose much?

 

[tim132]

I've been incredibly lucky mate, I've only lost one chromis so far. My tangs were riddled with it all of a sudden, a fine powder and discoloration. I still think it was velvet but that usually kills quickly so...

All fish still alive and doing well...
Blue Hippo
Vampire Tang
Kole Tang
Chalk Goby
Yellow Coris Wrasse
Cleaner Wrasse
Bi-colour Blenny
Foxface
2x Occelaris Clowns
5x (now x4) Chromis

You ever had the experience/displeasure of having a fallow period?

 

[Ludders]

I agree that does sound like velvetand glad you were lucky.